Can anyone shed light on whch of the pontiac motors are good strong runners for 55 Pontiac 4 dr. And pics would be fricken awesome. I am looking at a 72 350 for my 55 but I would love to see some squeezed in there first.
I can't help with pics but I really wouldn't waste my time with the 350. They didn't have that much power and weren't really any better on gas than a 389 or 400. Just my .02
In your opinion, which way would you go? I'm not building something for street rodding, just a cruiser.
Physically ANY Pontiac v8 will fit in your 55 its just a matter of mounting that gets a bit tricky. 55-60 used a front/chin mount with 2 side mounts on the transmission, so a 389 from 59 or 60 will bolt in with the correct transmission. Or any other engine from that era would work as well. Putting in any later model 326-350-389-400-421-455 is no big deal you just need to fabricate 2 side engine mounts and a single trans mount.
Like bryan said...a 55-60 engine will be a bolt-in...almost. When using a late 56-60 engine with the old stock 55 slant pan hydro you'll need to grind a little off the edge of the crankshaft flange to get the engine-half of the fluid coupling to fit flat against the crank flange...if you don't, the front pump of the tranny will be destroyed shortly after start-up...don't axe me how I know. 55s had 287 cu in 56s had 317 cu in 57s had 347 cu in 58s had 370 cu in 59 and 60 had 389 cu in and will make a light 55 fly! No use in photos because the 55-60 engines all looked the same and bolt up the same... I'm using a 1957, 347 bored out to 370 cu in in my 34 ford coupe just because I LOVE them old pontiac engines. If using a manual transmission, trash the old 55-57 stick bellhousing and go with a 58-60 bellhousing....the later ones mount a chevy-type transmission and will accept everything from a muncie 4 speed, saginaw 3 and 4 speed to a T-5 overdrive trans....the early [55-57] bellhousing only accept the antique and weak select-a-shift 3 speeds with terrible gear ratios. Pure junk.
Nothing wrong with the 350 in a cruiser, it certainly will be easier to get parts for than the stocker. All Pontiac engines share the same block design, with upgrades and some internal configuration changes. The 350 would let you run a 200R4 without as high a degree of killing it, too. The rough spot in 55-57s is steering clearance. The starter is on the left, and originals the exhaust actually dumped at the front and went around. Some guys mount the motor offset an inch or two to the right to make the room needed for a rear dump to clear everything.
400. Plentiful and powerful with decent mileage. A friend has a later Poncho in his 55; e used two RH manifolds to clear starter.
Similar situation with my 55 Oldsmobile. 74 Pontiac Trans-Am subframe worked in beautiful. Very little modification to put the body and bumper on it. Used an early 70's smallblock and short tailshaft turbo to stay forward of the stock X frame. Used a 70's column to angle out to the forward steering box. Fabbed a header panel to channel all air through the radiator and can change all the spark plugs easy just leaning over the front. Works for me............
Times two on pure junk---left one on the street back in 1963---heart shaped hole in the case. It was factory behind my 347 tripower bored .125. Sure sounded good til the junk tranny let go. Ah. memories.
Originally I built side mounts for mine with 2x2 1/4 tubing and flat plate . Also factory frame mounts bolted to it and made an adapter for the driver side to move the mount forward because of the steering gearbox. The earlier engines the frame mount is solid and the rubber mount is on the engine. But in your case it will be the opposite and do something like this http://starchief57.tripod.com/techtips.htm#late The 2 bolt pipe attatching manifold are smaller on the end and have a little more clearance around the gearbox also if you want a rear exit on the driver side. I mounted mine up higher than stock and off to the passenger side. Here's another example in this 57, same deal as the 55 http://www.jalopyjournal.com/forum/showthread.php?t=112566&highlight=dirty+pontiac
421 is also a good engine if you can find one. About any of them will take a severe beating. I would tell a story here but it would make me look real bad.
When I had my 56, I was going to update the powertrain with a 400. The newer engines retained the front motor mount provisions, so I was going to bolt it in using the original mounts and fabricate the side mounts accordingly. Don't think about using the newer engine's timing cover as a motor mount like the 55 has as the later engine's timing cover is aluminum instead of cast iron.
I just finished a 1968 350 poncho and a 200r for my 58 carryall. U can damm neer get them for free. With a few tweeks u will have a good strong cruzin engine.
I should have mentioned I now use a Hurst front engine mount which is only intended for the 55-60 steel covers. I put on a 60 steel cover on my 66 389 , which could also still use the stock front bracket and mount. The 60 cover is the first year of standard cooling and the last year of the steel cover. I also built side trans mounts of the back of the engine and a rear trans mount.
So, let me get this straight. Use a 60 steel cover on any 60's-70's pontiac engine and it will bolt right up with the 55-56 stock bracket and mount? I've also read about transmission clearance issues with the "x" portion of the frame? Has anyone ever cut out the"x" and just added a couple of crossmembers?
That only takes take of the front mounting, it needs more than just a single rear mount. It needs side rear mounts on the engine. Also on the cover originally it had a piece of cork spring loaded against the back, bore it a use a newer stye seal like this http://www.pontiacsafari.com/L1Garage/FrontSealUpgrade.pdf The side mount could be made to tie into the factory trans crossmember. I couldn't do it that way because of my headers. A short th350/400 will go right in. A long tail trans could cause some issues, but not worth taking the x member out for. My build thread has alot of this stuff covered in pics on how I did it. One thing I can't verify is if newer manifolds will clear the upper control arms in the stock mounting location of the engine, the 287 manifolds are pretty small and flat.
No matter what, putting a later model Pontiac engine is no more work than putting an off-brand engine in! Bored Over- Not sure you can just swap the early cover on the later engine, plus you would have to fab up side transmission mounts. At that point you might as well fab 2 side engine mounts since doing a singular rear mount is a snap. I don't know what transmission you would need to use to have to cut out the X member out. I had a Small Chevy with a TH 350 mocked up in my 57 frame at one point and there was still GOBS of room.
If anything use the bracket and front mount on the newer engine to set the engine in place to build the side mounts. Just have the manifolds on to make sure they clear the steering gearbox. The crank snout is 1/4" longer on the newer engines as well, so the crank will stick a little furthur out. If you read thru the seal article, the alignment tool is a must. I borrowed it from the author to do mine.
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