I've cut up junk headers for the flanges before. But, I met these guys recently at a swap meet. They'll make you flanges if you send them a gasket. Tim 530 878 0351 Dan 530 637 1629
Considering 1.65 rockers with existing cam.[/quote] Minty, Forget the 1.65 rockers on a stock Cam..... I did this due to not haveing a good set of 1.5 rockers & got a good deal on a set of GOTHA 1.65 rockers. IT SUCKS ASSS! They dont sound good, Ya run outta power at a low RPM, and with a 1.65 Rocker you CAN NOT run a big cam due to valve/piston clearance. Stick with 1.5 rockers & run a bigger cam.
Thanks,DeSoto.That is the route i will take.Good excuse to buy cam kit.Since we are on the subject,Comp cams shows cam kits fit all engines 55-80.With all the different variations in rockers and valve length will these springs work in my 56?Thanks for all the great feedback.
Probably not without machine work. Just because any cam company says the springs will work with the engine/cam combo does NOT mean it'll work with what you have. Manufacturing tolerances on early motors wasn't that great, machine work (or hack work) the heads have seen since they were new and normal wear will significantly effect the way the amount of machine work and fanagleing needed to be really correct. We've found that poncho motors have a relatively small window when trying to balance the set-up for correct spring installed height, adequate spring pressure and retainer to guide clearance. To be really right the heads should be dialed in for the springs your going to use....that usually means pulling the heads and machining the spring seats and guides for the additional room performance springs sometimes need. We've seen soooo many motors that have had "kits" tossed in without a proper mock-up and assembly its not funny. Checking geometry is a must and its not uncommon to have to order a set of custom length pushrods to make it right. Spend money now to save yourself more down the road. -Bigchief.
Another one for the Pontiac guys... Anyone know where I can get a motor/ engine mount to fit a '66 - 326? I'm looking for the type that is a single piece and mounts to the front of the engine.
No such thing (that I've ever seen, anyway). The only saddle type mount for Pontiac engines fits the early ('55-'60) blocks with the cast iron timing cover. The '61 and newer Hurst mounts bolted to each side and extended forward.
Following this thread and found it very informing. I've got a little issue going right now with '57 pontiac heads. Hope someone can give advice. I freshened up the original 347 and added a tri power setup. Installed it and ran around town but started having backfire (intake) issues after the first 50 miles of break in. Traced it back to the #7 exhaust valve. The rocker nut (nylon lock nut ) backed off so far that the rocker fell off the pushrod and valve stem. So I swapped nylon nuts for stover nuts. Drove about 50 miles and the same damn thing started happening. #7 exhaust backed off. Figured it was time to get serious and swapped in poly lock nuts (w/ set screws). Damn. same thing happened again. #7 exh nut backed off and the set screw would have fallen out had the valve cover not kept things in place. To make matters worse, it looks like the 3/8" press in stud on the #7 intake decided to slip out about 1/8" also. This time I noticed that the original stamped rockers were not as full of oil as they should be. Turns out the engine builder pressed solid studs in instead of oil through studs. Arhg! I'm "guessing" that the #7 intake stud backed out because of the added force needed to overcome the exhaust charge after the exhaust valve locked closed. I'm thinking that the lack of rocker ball oil attributed to the nut loosening. So, I need suggestions. I've got two ideas now. What do you think? A) Remove the rockers and drill out the push rod tip with an oil hole ala SBC style. I don't know what size port or the orientation. B) Remove the heads, tap for screw in studs. Modify rockers like option A above. I really don't want to pull the heads if I don't have to. Are there any chevy rockers that come with push rod oiling and would match '57 poncho geometry? 1.5 ratio. Oh and by the way. Those 50 mile break in trips kicked ass. I love this power train.... while its running. I need to get this beast back on the road.
I have a 347 out of a 1957 GMC truck in my T Model Ford Modified. It currently has the truck 3 speed gearbox. What would be the best way to get a modern 5 speed behind it. I'm in the UK so buying an adapter kit from the USA would be no problem but importing a full size gearbox would be expensive - so I need to narrow down the gearbox choice to one available over here in Europe.
I have a question about the GMC/Pontiac bellhousings. When did GMC stop using Pontiac engines and do the Olds bellhousings used in trucks have the later BOP bolt pattern? I'd like to put a Pontiac in my '59 Chevy truck but don't want to be limited to '55-'60 model years. What bolt pattern is on the GMC V-6?
Used 1955-58 GMC truck v8 the 1/2 ton ----2 ton used pontiac the2 1/2-3 tons used olds v8 the chevy of the same time and size used buick I used to put 1960 389 in a 57 GMC pickup it had 390 gears I put round track tires on the rear out drag all the boys. they though it was a 347. I'd put a Mc # 10 cam and TRW lifters it turn 6200 blow a little oil but they couldn't beat it.
But you get an extra 100hp from 55cu in just from it being there My head hurts from reading that mess...no doubt there's some good information there somewhere...I'll stick to my 400's with the "outdated heads" and make less power apparently...there's no replacement for displacement, or piston speed...
The only thing Ive ever encounted that was weird is they made different valley pans for different manifolds ,,,,,,,,Heads interchange Change heads and bolt on horsepower 6x is the heads I remember .Still kicking myself in the ass for selling my 455 for 450 ,With the ramair 3 cam .Thought horsepower was around 250 .Thats what you get for reading .Pontiac lied about the horsepower rating for that year.....................
Different valley pans for different manifolds??? The valley pan overlaps the block (frnt/rear) and the lower edges of the heads. So, why a difference because of manifolds? While I'm all with you on bigger is better. I'm not sure I'd agree with 100 more HP from those 55 additional inches given everything else is the same (cam/compression/heads, etc). That's roughly 2 HP per cubic inch more. It's possible, but certainly not probable if the other things remain equal
I guess from 4 barrell to 2 barrell ,I just ran into this once ,Im no expert ,RebUilt a total of three my whole life .
ASSuming you're responding to MY post? I just don't see how that would have any effect on the valley pan. I've seen some with the PCV towards the front, and some towards the rear. But, I'm sure they would interchange with no issues
I was just teasing, sheesh...most of the guys around here won't touch 400 or 455 motors anyway because they're too new...I have nothing against 455's, I just prefer 400's...if I were actually building drag motors to win money, it'd be a stroker motor anyway...I do have a hard time believing that you're bringing in 2hp per cubic inch difference between a 400 and a 455 with the exact same work done to both motors...if it was a 60-70hp difference, sure I could see that...but I'm just some dumb kid that tinkers with cars, so there's a LOT that I don't know...
In the 70s they changed. They drop down father and will hit roller lifters if you use them. I have torn apart and rebuilt many Pontiac and there is no way you will make 100 more HP by going 55 cid more. For one , friction in a 455 is more than in a 400, also MPS "Mean piston speed" is incredibly alot more in a 455. You will make more torque and horsepower if all things equal but not 100 hp. I have 4 455s and many 400s and got rid of 2 428s as I went with 455s instead as big journal is big journal so why not go bigger. Now with the stroker kits, the 400 with the 455 crank rules the roost. I also have many sets of heads and intakes. The stock one is actually good from 1967- 1972 . 1972 is the best as it will cover up the crossover exhaust port on newer and older heads. The 67-71 will not cover the 1972 on up head port. Its easy enough to fill the area up to seal the leak but thats another story. Also the 1969 Pontiac got a different timing cover and waterpump that then stayed the same till 1979. Up until 1968, they used an 8 bolt water pump and then went with an 11. The 1969 also had a long and short water pump. Now with that said, I prefer the open plenum manifolds over the dual plane, as I use power in the top end range and try to lessen the torque on the low end. I still cant hook up, even doing 20+ mph and hammering on the throttle. Thats with MT Drag radials . I do 0-60 ft in 1.67 seconds with my street driven car and 11.7s in the 1/4 with non ported heads. And its all in a 3810 lb car with the inferior 400. LOL.
Rabid Whippet, you and I haven't gotten along all that well over the years...yet I completely agree...just don't wash your grimy parts in the dishwasher at my house hehehe...
I never knew we didn't get along? Hey we may have disagreed about the dishwasher but that would be the only thing and its just opinions. All is good and always has been on my end. Oh also the dishwasher did smell a bit but after rinsing it a couple times and running the sterile cycle, all is good. I won't need to use it again to clean parts as my Hemi is real close to firing up!!! Real close!!!!!. I told my wife what I did and she didn't seem surprised at all LOL.
No idea where PAW sources their parts from, but made in China doesn't seem that likely. I know .030 389 pistons were a lot more than standard 400s and I should have checked my block for core shift and just punched it .055 or so instead of .030 if it would have taken it. I think I finally sold the thing to a guy, he gave me a deposit anyhow, then dropped off the map, so who knows. Any reason you can't put the late front cover on an earlier motor, as long as it has side mounts, and take advantage of using the late water pump? I know it bolts up, but I've heard you might have issues sealing around the crank snout.
I wonder why the crank seal wouldn't fit early and later cranks, I thought the front snout is the same diameter? And Whippet, I was just ribbing you...I'd really like to find the secret to getting 800hp out of my 400, at least the secret that doesn't involve seeing my rods peeking out the block to say hello...speaking of rods, how common are stock forged rods and cranks?...
Ok, so you tested 455 parts on a 400? That's hardly fair and justifiable numbers...it's like throwing an 850cfm double pumper on a 289 Ford and saying it made 100hp more on a 351C Ford...you can't just toss parts around between motors and expect accurate results, and I'm sure you know that...I'd still put a well built 400 up against that 467 and I'm guessing it would be maybe a 50hp difference...
Dont bother with stock forged rods. Ace at Pacific Perfomance Pontiac can set you up for brand new ones all checked out for around $200 or better yet, H beam rods.
That's a pretty fair price, are they smoothed and shot peened? I've been checking prices on forged pistons lately and found sets in the $400 range, but I'm thinking with the low compression I'm running (9.5:1) I'll be safe running Keith Black hypereutectics without too many issues (hey, someone's gotta put on a fireworks show at the track, right? )...anyway, I'm gonna go slap an 1100cfm carb on my 326 and see what it runs on the dyno compared to my buddy's 601 stroker
Don't forget the added friction with the 455. Like you have said, you cannot take all parts off of a 400 and put them on a 455 and expect the results to somehow compare as a 455 can deal with alot more duration and needs more air fuel. Thats like comparing apples to watermelons. You just can't compare it. Again the best of both worlds would be the stroker small journal 455 crank with the Ross pistons and H beams in a 400. Alot stronger and less weight, friction and brand new parts without any cycles, and more meat and potatoes around the crank. Bolt on a set of out of the box Edelbrock heads, run a small roller and get 520 Hp and 570+ all under 4000 rpm on pump gas. Screw that 13-1 compression. I like to drive on the street and not pay 10+ a gallon for race gas. There is no reason why you cant run 600+ easy horsepower on pump gas with all the aftermarket parts Pontiac has nowadays.
The Jalopy Journal
