Pontiac V-8

Anyone got experience with a Pontiac V-8? I picked up a virgin 400 for my 90 XJ for $100. Does this motor accept HEI? Does it use standard Chevy motor mounts? I realize parts will cost more than SBC, but the HP and torque will be well worth it!

This might or might not help you some.

http://carnut.com/specs/engdim.html

Check out T-A Performance (www.taperformance.com, I think) since they specialise in B-O-P (Buick-Olds-Pontiac) peformance parts (if you're going to use a Pontiac 400, get used to seeing that B-O-P thing...) and you're off to a good start.

You may want to look into MSD P/N8563 & 8528 for distributors, and either a Crane, Crower, or an Erson cam for good results - I've used all three in those engines, and I'd be hard pressed to select a favourite.

Edelbrock for induction, and you might want to think about converting it to fuel injection (which Edelbrock can do most or all of, right out of their catalogue.)

Anything else I can try to help with? I haven't done B-O-P performance in a bit, but I can dig around in the back of my mind and see what else I can come up with for you if you want...

5-90

90KrawlerXJ said:

Anyone got experience with a Pontiac V-8? I picked up a virgin 400 for my 90 XJ for $100. Does this motor accept HEI? Does it use standard Chevy motor mounts? I realize parts will cost more than SBC, but the HP and torque will be well worth it!

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Are you SURE it's a Poncho motor? Being a v-8 it SHOULD have HEI, motor mounts will be Pontiac, and it has about a snowballs chance of fitting in the XJ's engine bay. Pontiac used the same external dimentions for ALL motors..265-455. They are BIG WIDE lumps. Power is easy to make from them...but like I said...you'll have a snowballs chance of finding a Tranny with a BOP bellhousing that's set up for a transfer case.....as BOP NEVER made a 4wd vehicle. You are looking at big $$$ to get a 4wd mainshaft swapped into a Th350/400

It would only have HEI if it were 76' and newer. You could get Olds 455's in GMC pickups in the 70's with 4wd. For performance needs go to www.performanceyears.com and visit the Forums.

-xj said:

You could get Olds 455's in GMC pickups in the 70's with 4wd

Click to expand...

What are you smoking????? Engine choices in GMC pickups are as follows.

1970: 307,350,396,454
1971: 307,350,402
1972:Same
1973: 307,350,454
1974:350
1975: 350 2bbl, 3504bb, 400
1976: 305 2bbl, 350 4bbl, 350 2bbl, 400, 454
1977:305,350,400
1978: same
1979: 305,350,400,454
1980: 305,350,400

All these are from a Chiltons Big Book from 1981, referencing a K1500 , and K2500.
Bellhousing is not too big of a deal, summit has adapters for under 100 bucks, BUT, there is almost no way a Poncho will fit easily, if at all, in a XJ engine bay.

90Krawler, where were you about 6 months ago, when I could have used that motor for my 81 Firebird......