zacht

iTrader: (18)

anyone out there make old popular pontiac engine sizes for our lsx cars? as in like a 389, 400, 421, 428, 455.... ive heard of a 421 stroker, but havent seen much popularity with it due to the piston design to get the cubes. i think its 4.030x4.125. i know we have 383's, 402's, 408's, 427's, 454's. but i dont want to put one in and play it off for a different motor. i guess i think it would be cool to have a 400 trans am or a 428 or something.

anyone else have these thoughts at all? or is anyone saying their 427 is a 428?

guess im seeing most shortblocks in popular chevy engine sizes and no pontiacs. would this be a little bit of different machining and some custom pistons to make up one cubic inch difference?

KCS

iTrader: (20)

A lot of rebuilt LS7's are actually 428's when a 4.130" bore is used.

I think MTI (from Houston) did a 455 GTO a while back, but they went out of business a long time ago. You can still find some of the old MTI guys around different Houston shops, like LME or HKE.

orangeapeel

iTrader: (18)

You mean like the 70's FE blocked cars?

Mighty Whitey

i've always thought the idea of bringing back the poncho heritage in to a late model LSx motor was pretty cool.

now, if only i could find a 3x2 manifold for an lsx motor, I'd go on and build a 389. lol

kmracer

iTrader: (1)

its kinda trivial really, but you can make whatever size motor you want, its just gonna cost you. play with an online CI calculator and see what combos you can come up with.

zacht

iTrader: (18)

man, i was thinking the same thing. like a sheetmetal intake with a flat top, and 3-2bbl tb's....oh man, how cool would that be at a car show????

but it sucks cause we already have to murder the cowl for 1-4bbl....lol

yeah, im going to check into these things. i just think that nostalgic cubic inch would be cool.

BlackScreaminMachine

iTrader: (17)

I have heard quite a few people with the same notion, you might be suprise what may come out at some point.

Rawr256

You ever looked at the old Poncho motors? All are big blocks, you aren't going to get it into a F-body with out some cutting of the sheet metal in the engine bay. The only modern car it could work with would be the GTO because of the extra space around the bay.

You could probably physically get the engine in there, but the second you wanted to do exhaust you would realize you had real problems.

$750 L98

iTrader: (7)

I think he is just talking about building a LS series block to the CI of an old school Pontiac, like the GTO 455. It would be neat to say, build a trans am with a 6.6 LS in it, maybe add a raptor hood and some 6.6 decals to the hood.

It's just for aesthetic/conversation sake.

zacht

iTrader: (18)

yeah your right on this....no im not looking to put in an old poncho....im simply saying lsx...with ci based off of old pontiac engines. any one else with a pontiac notice that mose aftermarket engine sizes are mostly common chevy engine sizes? heres a scenario....your at a car show...with a stroker in your ta...wouldnt it be cooler to say, "its got a 455" vs. its got a 454.....i mean. you know how many old timers would be like, why the chevy motor....or something, im simply saying.

on the other hand, bringing up the 6.6, i think a 402 qualify's for a 6.6, so i might rock that idea....

RevGTO

iTrader: (12)

Pontiac 428 was actually a 427 - 4.125 x 4.00 - same as an LS7, IIRC.

370 was the Pontiac engine size for 1958 ... that's a popular aftermarket LS1 build. I don't think the are any Pontiac 370 emblems you could put on your car. Like you say, 402 = 6.6 and that's a good match.

disc0monkey

iTrader: (10)

the biggest thing to get a similar feel is to get the bore and stroke close and get a cam thats gonna idle close to a factory raIV cam (big cam wiiiide lsa like 117). leave it fuel injected and it'll be sick