Hi all! I've got a '40 Chevrolet Special Deluxe Coupe, all origional and my grampa and I wanted to spiff it up like the one he had in the service. We wanted to swap the origonal 216 straight 6 for a 270 GMC (mainly so we could get rid of Chevrolet's "dipper system"), swap the 3 speed column shift for any sort of floor shift (I couldnt find any conversion kits). We want to keep the "economizer" rear end in it now, but since it has a "torque tube" instead of a open driveline, that may not be possible. Now for the nitty-gritty... We have a GMC 270, and were starting to look for transmissions. We may have access to the origional 4 speed that went with the engine, however we dont know if we can mount it to the car. I think the engine came from a 50's pickup... If that doesn't work, I was also looking at T5 transmissions from 80's S10 pickups. I wasnt sure if that would fit either. I know that the S10 transmission has a more foreward shift linkage which would be ideal for the car, but I dont know... That's why I'm here! I would like to cut down on the customization to keep the origionality of the car. Any advice will help! Thanks! Pete P.S. Here are some pic's on the car...
A quick update on the car... I have got a ton of parts ordered. The major parts are the wiring harness from Rhode Island Wiring, the engine (previousley mensioned) and we are still thinking about using the 4 speed transmission from the GMC truck. Anyway, I have been buisy with end of the school year stuff and havent got much done besides get the engine running better. The guy was a real dingleberry and just slapped a 12 volt battery in it and didnt even bother to change over the alternator, or coil, so when I looked at the stock coil, it was exploding out the side, and the the guy had just disconnected the alternator, so I put a new coil, voltage regulator, and alternator on it and it runs like a top now. The clutch still rattles like a rattlesnake and the transmission still grinds like I dont know what (probably attributed to the clutch) but that is tomorrow's job. I'm going to pull the transmission out of it and see if I can fix both the clutch and the leaks in the transmission. We'll see what I find... Pete
Pete- you've got a real honey there, not too many '40 coupes left in that shape. I can't help much with the 4 speed swap (never done it) but I know in the past there were floor shift linkage kits from a variety of companies. Every once in a while you can snag one at a swap meet or in a parts car. I passed on another '47 Chevy a few years back that still had a "J.C. Whitney" floor shift adapter for the factory 3 speed. The asking price alone was worth it but I didn't want to mess with another rust bomb. I guess just keep your eyes peeled on the classifieds section here and/or your local swap meets and you may be able to grab one. The 270 will wake that old girl up pretty good. Otherwise best of luck and post up your progress. Doesn't look like she needs that much to go down the road again!
Pete, you got that car from Albuquerque right?On Hollywood street?Sounds like you are in the right direction with the 270,I would go the T5 route,you get the floorshift and the great gears.If you dont mind going 5 lug,55-57 rear end will pop in there and use 49-51 hubs/drums up front.If you want to keep it six lug,go with a late 80s Nissan rear end but you will have to do your homework on gear ratios.Does that license plate topper say Little America?-Jaime
The truck 4 speed probably has a "Granny" 1ST gear that would be all but useless in a street car. Going with any modern trans will mean converting to an open driveline which will be a good thing. Check out Chevs of the 40s for all of the hardware and trim pieces you need.
Wow, thankyou for the quck responces! MonkeySpunk79: I just looked on the JCW website. They have all kinds of transmission stuff, but no adaptors. I'll keep my eyes peeled at the local swap meets, but I'm still not quite sold on using the 3 speed. The T5 is looking more and more appealing which brings me to my next point. Thankyou for the advice though! MistGreen50: I sure did! How did you know? I like the idea of the T5, the only catch is the torque tube conversion/ new rear end. The T5 I would be using would be from the 90's S-10 pickup trucks. It has the mechanical speedo and more foreward shifter location which would be ideal for the car. I might use the rear end from the S-10 I pull it from, but it depends on the measurements on the rear end. I would like to leave the car as stock as possible, so the torque tube conversion would be my first option. Another option is an old Volvo transmission that my grandfather has out back. It was rebuilt a few years back, but never used. I think it is a 4 speed with an overdrive. I'm not sure if it is a torque tube, but I will give it a good look this weekend. I like the 5 lug idea as well. It would be a little more pricy, take more dumpster-diving, but probably have a better outcome. And yes, the license plate boder says "Little America, Wyoming" Thankyou for the advice! aaggie: I never thought about the granny gear! I cant believe I missed that! Thankyou so much for pointing that out! Chev's of the 40's is a great catalog, almost everything I ordered (exept for the wiring harness) was out of that catalog. The one thing it lacks though is the dashboard, and the trim pieces for the pillar going up through the center of the wind shield. I need a new dashboard because the old one was fiddled with by the previous owner and overall is pretty boogered up. If I can, I might try to pull a complete dashboard from another car; I could probably find one at a swap meet or something. Thankyou for reminding me of the granny gear... that would have been catastrophic! Thanks so much guys! I think I have narrowed it down to either the T5 transmission or the Volvo transmission, unless it doesnt have a torque tube setup on it and/or won't bolt up to the car with any conversion kits, in that case I would just use a T5. The 3 speed is still an option, however it is a little difficult to drive with just because of the huge gaps between the gears, in first gear it idles at 10 or 12 mph! Anyway, I'll keep doing my homework, and I'll figure something out soon. As of now, I'm just going to get it in driveable condition, so I can putt around while I'm rebuilding the 270. Thanks again! Pete
Pete,I had seen that car several times before.Im sure you saw all the cars the old man had across the street including the 55 Nomad.That street that Hollywood "T's" into where you are parked in the pic,well across the street and ditch,where the pro panel fence is....thats is my friend Randys place.
Haha, it's a small world! I can't remember what the guy's name was, but it should be on the bill of sale which is at my grandparents place. I'll look it up the next time I'm down there. He is down hollywood street, I think it was the 2nd house on the left. It was an adobe house. The guy had a few motorcycles parked out front and an old Plymouth Marauder. Yea, there are some cool cars down that street, I cant remember all the cars the old man had, but I know I was really wowed by them! Unfortunately, our guy was anything but a mechanic, so really we are cleaning up after him and his horrible wiring. If he would have just left it, it would have been so much easier to diagnose and fix any problems with it. He seemed like a nice guy though, subconsiousley ripped us off pretty bad, but never the less. Pete
Another update on the car. My grampa met a guy at lunch today who a referred us to a place that I'm sure some of you guys are familiar with. It is Patrick's Antique cars. They specialize in rebuilding GMC and Chevrolet Striaght 6's and Ford Flathead V8's. Anyway, my grampa talked to the guy for a while and we figured out that a 261 Chevy is the best option because it can be bored out to a 270+, will fit with the motor mounts, and we will not have to move the radiator foreward. Also, it has a full pressurized oil system unlike many other Chevy's of that era. We have already bought a 270 GMC which we are planning to pick up here pretty quick, however we may sell it after we measure it and see how things work to get a 261. The guy my grampa was talking to had 3 of them sitting around, so I would assume that they are availible, he also said that the 261 with the truck bellhousing would bolt right up to a T-5 which would bolt right up to the 55-57, 5 lug rear end (just as Mist Green said). So, some more blue sky thinking and like usual, another change of plans. What we do know is that we will most likely be going with the 5 lug systems from the mid-late 50's cars, and a T-5 transmission. Pete
Here's the new plan after talking with Patrick's Antique Cars and Trucks: -270 GMC. -270H GMC head (H is for hemispherical.) -Dual Carb Intake. -Split Exhaust. -235 Chevrolet Harmonic Balancer. -1948-53 Chevrolet Truck Bellhousing. (Casting No. 3701433) -Saginaw 4 Speed (with 2 I.D. ring meaning 3.11 first gear.) -1955-62 Chevrolet 1/2 ton Truck rear end (Casting No. 3707340). -Patrick's 3.38 ring and pinion kit. I went down to a salvage yard yesterday, couldn't find a 1955-62 Chevrolet rear end, but I did find a 1958 GMC 100 with a Dana Spicer 45 rear end. I saw on a few other H.A.M.B threads that the Spicer 45 is somewhat interchangeable with the Chevrolet truck rear end and that Patrick's kit should work with the Spicer (although I haven't asked Patrick himself.) I took some measurements on the Spicer (56.5 in from backing plate to backing plate) and found out it was 2 inches longer than my '40 Chevrolet (54.5 in from backing plate to backing plate.) First off, are these measurements right? I didn't have a pencil to write down the measurements when I got them, and knowing my brain I could twist those numbers up real easy. I've been looking around on the internet, and can't find them anywhere. They've got to be somewhere, does anyone know? Secondly, if the measurements are correct, does it make that huge of a difference appearance wise? I probably have enough room inside the wheel wells, but I'm not sure how much of a difference one inch on either side makes. Also, are there any easy tricks to shortening the axel length even just a little bit? Thanks! Pete
This isn't mine but I saw it and was impressed with how clean it looks. The front end looks to be completely stock. The metal work is meticulous too. It has a later inline six in it too, Normbc9
The spicer 45 rear does not share any parts with the Chevy rear. It's a completely different animal. The spring pads should be in the same place as a Chevy of the same era (55-59) but other than that nothing interchanges to my knowledge. FYI - Some of those spicer 45s had 3.08 gears in them. When you are measuring for a rear diff, you should measure from the wheel mounting surface to wheel mounting surface, not from the backing plate. On the 55-59 rears I think it is 60", if I remember correctly.
Wow, that thing is sweet! No kidding, with a paint job like that, the sheet metal and bodywork has to be laser straight! I may hack some people off by saying this, but the standard 350 Chevy, automatic transmission, mustang front end, etc. doesn’t really do it for me. I haven’t seen many '40 Chevy's today that keep the originality of the straight six. I respect people for doing that. It adds more character to the car. I’ll stop now before I get reprimanded. Thanks for showing me! Pete
Thank you! Yeah, the interchangeability seemed a little too good to be true. On the other hand though, the 3.08 gears would be even better! I just dug up some info on another website saying that the '58 GMC 100 with the hydramatic transmission had the higher gears. They are not interchangeable with the 3.90, according to Bill Hanlon and his GMC Master Parts Book, however. I don't mean to plagiarize, so here is the link to the website (Thanks Bill!) http://talk.classicparts.com/showthread.php?t=956 Anyhow, if the truck I’m pulling this out of has the hydramatic tranny (which I'm skeptical about) then that would be great! The 3.07 gears with a pair of 7x10’s on the back of it (101 inch circumference) would yield a top speed of 124 mph at 4000 rpm in comparison to Patrick’s 3.38 rear end putting it at 113 mph at 4000 rpm. Cruising at 77 mph would be a piece of cake (2500 rpm)! The only way to check is by pulling the cover and looking for those numbers. I’ll head back down there on Tuesday to check it out. Thanks! Pete
Just one more thing you might want to thing about with all the upgrades, stopping. I have had a few 40 chevys and upgrading the brakes is always a plus. If nothing else I would convert to a dual res. master cylinder. Also I ran a 250 with a 4 speed in my delivery for years
Haha, your absolutely right! I live at the top of a fairly large hill, and coming down is an adventure every single time. True white-knuckling. I'll look into that. I'll slap a dual res master cylinder on and see how far it goes. I suppose the 55-62 Chevrolet rear end (or Dana 45 ) with bigger breaks might help a little, but we'll see how it turns out. Can always put more on... Thanks! Pete
Here's a picture of my grandpa's car (the one I'm roughly modeling it after.) On the right is my grandpa (Jim Smith) and on the left is his partner in crime, Leroy Whacker. Sorry, the picture is tough to see. Pete
I put a 70 ford half ton rear in my coupe and it fits great, plus the ebrake is easy to do. I ran a 250 with a 700R4 and 3:25 gears which was to tall for the six. The original engine came with a turbo 350 and 3:08 gears. These 40 chevy's are easy to work with, trans mount is easy to modify and keep the ebrake parts. Everything is riveted together so its easy to take apart. Those truck rear ends are easy to find. good luck and I hope I helped some.
I'm sorry I don't have any advice to add. I just wanted to say that it looks like you have a nice car to start with. It looks like it is really solid and the paint isn't even in too bad of shape. I like where you are headed with this build, keeping it looking old school while adding modern touches to make it more reliable and a little more user friendly. Doc
Wow! If you say that the 3.25 gears are too high, then the 3.08 gears are way out of the question. Thanks for the input. Boy, that kinda worry's me about the 3.38 gears too. Those may be too high as well... Thanks, Pete
Lawman: Thanks! Docmike: Thanks! Haha, that's the idea! Really the only thing going for the car right now is that it is completely rust free (thanks New Mexico!) Otherwise, the thing has basically been hacked together by ducktape, sheetmetal screws and a really long spool of red wire by the previous owner. It's gonna take some TLC. I'm starting to think that I should just pull the whole car apart and start from scratch. Almost everything needs replacing... As for paint, I think I'll leave the origional paint on it. Just polish it up and spray a few coats of clear enamel on. Gives it kind of a sleeper look... Thanks! Pete
Norm, this one has the dreaded LS3,sorry no inline(and I really like the 6 cyl too). The front end is very modified, custom grill, custom hood, custom bumpers, etc. Thanks for the compliments though. BlackJack, that is a nice looking coupe. I like the direction you are headed.
Another update on the car... I have a Saginaw 4 speed, floor shift kit, and a driveline with a yoke to fit on the tranny. Bought them on the classified ads from Andy52 on this very website! Special thanks to Andy, just an absolute prince of a man. My grandpa, him and I swapped stories for about an hour out in the cold, and we could have gone on for the rest of the day easy. Andy, if you ever get to read this message, Thank you!!! Pete
We hit the jackpot! Met a guy named Steve Cattalini, a local 6 cylinder guru, who has got a bunch of stuff we need! A 1948-53 Chevy truck bell housing, 235 harmonic balancer (not pictured), and a 1955-62 Chevy 1/2 ton rear end. Cattalini was even nice enough to deliver the rear end! Should be here some time over the long weekend. Last real thing on the list is the infamous 270H head. This is gonna take some time! Parts, Parts, and more Parts! Pete
man you got a sweet little car there. And im pretty amazed your using the 270 gmc(im an inliner lover got 2 270s, 2 261 chevys and a couple 235s sitting around and 2 235s in trucks-hot rodded of course). The 270 will do quite nice in that car even without the H head(thats gonna be a crazy tough one to find). Good luck on this car. Im surely gonna be following along on this build.
Hey thanks! Wow, that's quite the collection of straight sixes! Yeah, the H head is going to be tough to find. It kinda makes me think, what advantages are there to the 270H head? Is it worth the cost and time to find one? About how much horsepower does this actually add? If I can find one, then i'll jump on it, but what if??? Knowledge never hurts! Thanks a bunch! Pete
great thread wish my grandpa was interested in anything! i may have missed some thing with the pick-up rearend. for me...poor choice 55-57 chevy car rearends are an easy swap, 5 bolt wheel pattern. they are also maybe hard to find! a nova rearend easy and cheap 8.5 modern parts available at the parts store. switch out the front brake drums to 5 lug! the brakes will be OK for your driveline. the master cyl. is the weak link (was in mine) i had to put kit in every 2,000 miles?? your clutch set up should hook up with the parts from a newer pick-up that had the peddles thru the floor (not sure what year they changed). now all of your peddle set up is hanging off the MC!! i know a guy that used to drill a hole thru the back of the old master cyl. and mount a upgrade dual MC behind the old MC and make a rod that goes thru to the new one
Nice looking coupe, good choice for power train. I'm building a '40 Deluxe coupe as well, using a 292 inline six, Muncie M20 four speed and nine inch Ford with a 3.50:1 posi. The 270 has enough grunt to move that car pretty well. I had a '40 two door that a previous owner had swapped the front brakes on, it had five lug drums. Must have swapped the spindles for parts with a greater king pin inclination angle at the same time, as the front end could not be aligned properly, at max. negative camber adjustment the thing still had 3 degrees+ positive camber. So keep the original spindles if you're swapping brakes.
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