First Poncho engine buildup Q's
 

Well this is my first post here and it pertains to my first Pontiac engine rebuild. Ive got a 455 that was being built by another guy who suddenly needed money and sold it to me pretty cheap. He was building it part by part as he could afford it from an article he found in a car magazine a few years ago... something like "the best street pontiac buildup" or something like that. It has an .030 overbore with aftermarket pistons, h-beam rods and i'll find out more about what is done once its apart. It is missing a few items like the oil pan, harmonic balancer, flexplate/flywheel... etc. Ive got a couple 400 cores sitting around so my question is (1.) will any or all of those 3 pieces interchange with my 455? Im going to send the crank out to be balanced and it'd be very bad to send it with the wrong parts!

By the way, just to break in the engine and have a little fun while i find a cool car to install this engine into... its going to power an '80 LeMans Wagon that i got for free because the car is ugly and the 301 in it is ready for pasture. Speaking of the wagon.. (2.) will 70's 455 Firebird/Trans Am headers fit this application? If not then is there a supplier for something like this? The car is completely stock and i want it to be a fun little sleeper!

Thirdly, and im sure it wont be lastly, a couple questions about putting a 4spd behind this engine. (3.) Can i use pedals & linkage from an early 80s Malibu? Do i have to use a 4spd that came from a pontiac originally or will any GM tranny work? Then theres bellhousings: will a buick or olds bellhousing work? I know they have the same bolt pattern for the block but im concerned about input shaft lengths and whatnot.

Thanks for any help! :beerchug:

Oil pan, harm. balancer and flywheel/flexplate should all interchange as long as the flywheel/flexplate will mount to the crank (check the crank hub and internal flywheel diameters).

Pontiac engines are internally balanced. By adding a balancer and a flexplate, won't you have to have the pistons,rods,crank, Harm. balancer, and flexplate rebalanced? Cost me 150.00

Canadian Kokanee is a** kickin beer!!

Umm, actually, stock Pontiac engines are "externally" balanced. That is, there is a slight imbalance built into the stock flexplate/flywheel that counteracts a like imbalance in the crank.

It is entirely possible to "internally" or "neutral" balance the rotating assembly and run a neutral balance flywheel.

It would be a good idea to find out if the crank was balanced already, and if it was, whether it had a Pontiac spec flywheel on it or not.

The harmonic damper is neutral balanced.

You will need a Pontiac specific bellhousing, but any of the popular GM trannies should bolt up.

Sorry, can't help with your questions concerning headers or pedals as I'm not familiar with the later '70s mid size and full size cars.

Thanks for the help guys... what sucks is i had two mid 60's Pontiac bellhousings a while ago which i sold on greedbay because being a ford/mopar guy (usually), i didnt think i needed em! Ive always been a closet Pontiac'er and im pretty excited about this project. When i get back in the spring i'll be looking for a 65-70 A-body or i'd consider an F-body 67-73. Nothing previously restored and no basket cases, location can be western canada or the northwestern usa. A '65-67 GTO/LeMans/Tempest would be ideal :cool:

To answer a couple of your other questions, yes, the pedal assembly from any G-body will fit.

Mad Dog makes nice headers for the G-body with the Pontiac, as does Indian Adventures.

If you plan serious power (>500 HP), I would highly recommend the Lakewood SFI bellhousing. Lakewood also supplies a heavy duty clutch fork .

Since this is your first Poncho, I would highly recommend you buy Jim Hand's book "How to Build Max-performance Pontiac V8s" by SA Designs. It is the most comprehensive study of the old Injun since the early '80s. VERY good streeter info there, and current through mid '04. Study the book, study your parts, and see how much of it "matches".

Jim

Well i rounded up a balancer off my 75 400 core and bought a new flexplate.. niether one has weights on it so im thinking the engine is internally balanced? Either way, the parts are there if my balancer guy needs em... havent had time to get the engine apart yet tho.

Turns out the 400 core has aftermarket pistons with dual valve reliefs cut in em... never seen that before. Plus it has a balanced crank! Currently soaking it to see if the block is saveable.

i agree with Will.....i just went thru balancing for my 68 400 (for auto trans)....the flexplate did not have weights on it, but it does have a set of one inch or so diameter holes drilled thru it in a certain area, creating an off balance condition, which i believe is counteracted in the crank to create neutral balance

be sure to use your correct flexplate when balancing the crank/rods...for good measure we also mounted the harmonic balancer during balancing