If you install bigger valves and raise the compression and get the right cam the H head is good for wide open throttle. If yours has a 302 head the ports are the same as the H. The small port heads do just fine for a driver.
A little more progress... Clifford headers are in - 3 days early too! They're really nice, fit perfectly. Thanks Clifford! The intake manifold cleaned up nicely in the sand blaster, and the carbs bolted right up. Only a matter of hours 'till this thing will be running! Thanks! Pete
Manifolds are on. Throttle linkage is cleaned, painted and drying. Just more odds and ends really. Still waiting on the 235 harmonic balancer and starter motor which should be here tomorrow or Saturday. It's getting real close. Six Ball: Thanks, I appreciate it. I've got just about everything crossed too. Fingers, arms, legs, lungs, kidneys, I really hope nothing goes wrong. Cosmo49: Yes sir! Will probably make a little plate to bolt on the bottom there. My worry is how the water is going to circulate through. I may end up drilling holes on either side of the tube that runs along the intake a few inches after the riser itself so water circulates nicely. I'm worried that they may fill up with air and never get heat. For water, I'll probably run a splitter off I the water pump outlet for the heater. That's my idea... Any advice? Thanks, Pete
Here is what I did when I converted an Offey 3X1 to a 2X1 for my Chevy 4 cyl. If you make a plate with an inlet and outlet and take water from above the thermostat and return it below the thermostat you'll have a constsnt floe of hot water to the bottom of the manifold. I think it would supply enough heat.
Good idea and nice manifold! I suppose I could drill a hole in the side of the thermostat housing which feeds water to the top of the radiator, then return it at the bottom of he radiator. That would provide plenty of a gravity feed. Possibly some sort of a siphoning effect. Thanks! Progress from today was minimal. I just went and picked up our 235 harmonic balancer, blasted and painted it. Also picked up our new starter which engages, but won't turn the motor over because everything is too stiff right now. Grandpa Jim also built the rear tube shock mounts, I welded them, blasted and painted them. Again, just odds and ends until this thing is roaring! This should be the lucky weekend for lift off! Thanks! Pete
Today was tough. Spent most of the morning looking for the bolt that holds the Harmonic Balancer on with no avail. I drove over to NAPA. They dug around for about half an hour and came up with one! Drove back to the shop and figured out it didnt fit. It was pretty strange. It measured out correctly - 5/8 18, but for some reason would start cutting the threads off the bolt after about 4 turns. Drove back over to NAPA. We determined it was a production error with threads that were slightly off (something like 18.3 threads/inch) They dug around for me some more and came up with a dye, but no bolt. Drove around to all the rest of the autoparts/ hardware stores nearby and came up empty. Went back to the shop, dug around some more and came up with a long 5/8 bolt. Cut the coarse threads off the end, went back to NAPA bought the dye they had dug up and cut new threads on the bolt. Great! Went to put the harmonic balancer on, banged on it for a while, but it went on about half way, then just stopped. Destroyed a set of pullers trying to get it back off. Drove to NAPA-closed. Drove to O'Reily and bought a set of fine-thread pullers. Back to the shop. Pulled the harmonic balancer off. Figured out there was a little lip inside the harmonic balancer which let it go on to a certain point then stop. It must have been for alignment of the fan belt or something on the 235. Cut off lip on the lathe. Still doesn't fit. Repeat. Pound back on and put bolt in. Roll around on the floor laughing. It's 10:00 pm. The only picture from today: Goodnight! Pete P.S. Does anyone know what these three holes lead to (see attached)? I can't seem to figure it out. Thanks!
Oil, Vaccum and Fuel lines are bent and in. Still waiting on a couple fittings, but that's just a matter of getting them and tightening them down. Rear Shock mounts are made and bolted in. Breather tube is sandblasted and painted. Thanks! Pete
Drive train is put together to present to the Senior Project boards. Looks great and the speech went really well! (The Engine is my Senior Project/ Exit Project for highschool.) Thanks! Pete
Thanks guys! Started work on the cooling system. Space was going to be an issue. Also found a nice big crack in the stock 270 water pump. (See attached) Must have happened when we torqued it down. Anywho, we were going to have to ding around with the radiator to get it to fit anyway, so I grabbed water pump off the 216 Chevy that came out of the origional car. It had no end play and plenty of resistance signifying that it was not worn out. It bolted right up and was about an inch shorter - good deal! It's still a little tight for me, so I'm going to try to get the radiator inside of the housing. That should give about another inch. Might be able to get the fan in too. Also sandblasted and painted the new/old Chevy water pump. More to come tomorrow! Thanks! Pete
Water pump is on. We dinged around with the radiator housing trying to get the radiator further foreward so we could get the fan on but after a few hours, we decided just to get an electric fan and mount it on the front side. We would probably have ended up needing one even with the stock fan anyway. More on that later. Overall, a pretty useless day... Thanks! Pete
We put the radiator on and fired it up today! Tuned it up and let it run. The radiator sprung a leak, and the water pump had a bad seal, so all the water ran out of it and overheated. That kind of put the kybosh on things for today. Also, I think the mains I put in the carburetors are too small. I also might try my hand at making a set of adjustable mains. Some of these Zeniths had them and I've seen sets that people have made, so I figure I'll give it a shot. Any advice is much appreciated. Thanks! Pete
Some of my zeniths have adjustable main jets. I don't know if there are internal differences but I'll be following this to see what you do. Another advantage of Zeniths is the changeable venturies. They are hard to find now but not too tough to make.
Thanks USA Tires Sign Joe! Six Ball: I'm working up a list of people I can call. Hopefully one of them knows what the heck is going on. Another thing that could be causing it to idle high is all the friction in the motor. I think I'll procrastinate things and let everything wear in and see what comes of it. Fingers crossed. About the Venturi's: I've got a few sets of Venturi's. I put the largest ones in, I think they are the 34mm ones, so that could be the problem as well. I need to talk to a carburetor expert. I hate not knowing these things. Haha, yeah! Stay tuned, this should be interesting! Today was fairly productive. Grandpa spent the day bondo-ing. Everything that needs to be covered is covered. Most things are sanded down to within tolerance for blocking primer and such. Thanks grandpa! I spent most of the day drilling out broken off bolts on the underside of the body. Amost every single bolt which holds the body to the frame and the running boards to the body were broken off. It was a long day. Thanks! Pete
More bondo work. The body is coming along nicely. Should be moving on to blocking primer shortly. Also, we tried our hand at fiberglassing. Grandpa wanted to give it a shot, so we did. There goes our '50's technology virginity. I think it turned out alright. I'll need to paint over it because wherever there was a hole, there is a big transparent spot - it looks kinda weird. Sorry, the pictures are pretty bad. Thanks! Pete
I've done the transmission swap on a lot of 235 engines using T5's with the shorter tail shaft. Also have the bell housings that the T5's mount up to. Let me know if we can help out
Here is the 6 lug rear axle that everyone forgets about. All of the 1970's and 80's full size Chevy K5 wheel drive Blazer rear axle are 6 lugs and only about 1/4" wider than the original axle. They have either a 3.42 or 3.08 gear ratio. Since you are using a non over drive transmission I would use the 3.08 gear ratio. I had a 3.42 in my 1955 Chevy truck and it would fly down the road with the original 235 and three speed column shift, but it still needed a little taller gear to keep the engine from revving up to much at 70mph. With the extras powerful 270 and saginaw 4 speed a 3.08 gear ratio would be easy. Also the parts for the Blazer axles are cheap and at every auto parts. You don't have to blow money on one of those 3.38 conversion kits and a pile of expensive bearings for the 1955 axle either. Also, the Saginaw 4 -speed is going to throw the shifter a mile back and into your seat. What is the plan for that?
And I just remembered, when you mount any axle in place of the torque tube system, don't forget the the torque tube was mounted on an offset originally and when you mount your new axle in place, the new axle will be a few inches off of center. You need to make an adapter plate to get the correct front to back offset. The 1/2" or so diameter alignment dowel that sticks up out of the original springs is not the true center in a torque tube system. If you just mount your new axle in place on top of that dowel, when you bolt on your rear fenders, the wheels will NOT be in the center of the wheel well opening by about 2".
Thanks Jason! Man, it hurts when people bring this up. I really appreciate the advice, it's just I already blew all the money on the 55-62 Chevy rear end and the 3.38 ratios. I know I screwed up. I made the mistake of believing Patrick's Antique Cars and Trucks who really doesn't care what I do. They just want to sell their stuff and make money. I can't blame them though, they're a business trying to stay in business. Anyhow, I appreciate the advice. I may end up referring to this again if the 3.38 does not pan out. The blazer rear end is a great idea. Like you said, very available! Thank you! Little progress from today. Picked up the new water pump, pressed on the 3/8 pulley and painted it. Hopefully the 3rd time's a charm! We also ordered an electric cooling fan which should be here tomorrow. Thanks! Pete
Patrick's sells good stuff and has lots of GMC six experience. You will be fine with 3.38s. Which Saginaw do you have. they are all the same in forth gear and you will have plenty of power for any of them but check out Patrick's catalog for the different ratios. I run a Dana 44 with 3.55 ratio and it would do even better with 3.38s.
Haha, everything is an opinion. I guess I was a little harsh. He does have decent advice, it's just that I followed it religiousley. I did not get second opinions. I'm a little sour because he sold me a pair of crap Fenton headers and sent me on the wild goose chase for the large port GMC head - which it turns out I really didn't need. I have the reccomended 2 I.D. ring, 3.11 first gear Saginaw. I am looking for an overdrive to slap on the back and give it a little more top end. There's only one way to tell what's best! That's to start it up and drive! Hope everything works! Thanks! Pete
I'm running a set of those headers. They are actually modified Chevy castings i think. They were the softest cast iron I've ever seen and I was worried they would break when I bolted them on. They have been in place for several years now with no problems. You are right about opinions. Some of the "experts" can only think about race engines and are willing to put up with a less than good driver to claim they have a bunch of unusable power on the street. I went to the local Inliner show yesterday and on the way home had my old pickup up to 80+ a couple of times. There was plenty left. It'll cruse 75-80 all day and that is good enough for me. Funny thing the speedo only goes to 90 but there os no peg so it just keeps going back around. I doubt it is very accurate.
No kidding! That's great! What size tires are you running on the p/u? The math I did on my car with the stock tires (600R16 - 28.36in diam.) said I would be turning 3,000 to get to 74.81 mph. Not exactally comfortable when the max is going to be around 4,000... With a set of oversized tires (probably a 750R16 - 31.14in diam.) which would only lower the the rpm down to 2,750 to achieve 75.29 mph. I hope I can find an overdrive! Progress from today was minimal. Just mounted the new electric fan on the radiator, then customized the housing so the fan will fit. See attached. Schedule is starting to clear up, so stay tuned! Things should get pretty interesting. Thanks! Pete
The Jalopy Journal
