245 bhp on a 3.1/3400/3500 hybrid-possible?

[no_doz]

90-92 fwd 3.1 with a good set of long tube headers & true dual exhausts, mildly ported & portmatched 3400 heads & LIM, 3500 UIM, crank scraper & good tune, stock 3.1 cam. also with either .030 thickness head gaskets or the heads milled to remove .030" off the deck

would 245 hp at the crank be feasible with a good intake & properly sized TB & 9.55 CR?

[1988GTU]

I dont think you can do 3400 heads on a 3.1.

[no_doz]

from what ive read you sure can, but 3500 heads wont fit.

also the heads would be milled .040" because i was wrong about the .030" part.

[Superdave]

It'll work but you won't make near that power. maybe 180

[1988GTU]

All that work to have less than or equal to bone stock 3x00. booooooo!

[robertisaar]

need more cam and compression to get those kind of numbers...

[pocket-rocket]

NEEDS MOAR COWBELL!!!

[robertisaar]

NEEDS MOAR COWBELL!!!

that brought a smile to my face....

[pocket-rocket]

that brought a smile to my face....

I'm happy I could help

[no_doz]

need more cam and compression to get those kind of numbers...

i figured as much-what about just going with a 3400, headers, dual exhaust, bigger TB, good tune, & mild to moderate port work/port matching & a crank scraper?

[robertisaar]

with a properly sized exhaust.... i'd say somewhere between 200-220. you start with ~180, so its not going to be much of a challenge to get to 245.

add a healthy cam to that combo and you'll hit it.

but

you would keep all of the stock smoothness, driveability and fuel economy if you just stuck a turbo on it. you would even be making more power too...

[IsaacHayes]

3400 heads will work on a 3.1 bore. 3500 heads however will only work with 3400 or larger bore.

245, nope, not without cam and compression like others said. And even then it might be hard to get there.

3400/3500 hybrid with cam/etc yes that's possible and even more.

EDIT: modded 3400 with a cam could get there too. Forget dual exhaust, not much to gain from that but weight.

[Superdave]

3.1 is same bore as 3400. So yes to 3400 heads. 3500 heads however will only work with 3400 or larger bore.

245, nope, not without cam and compression like others said. And even then it might be hard to get there.

3400/3500 hybrid with cam/etc yes that's possible and even more.

EDIT: modded 3400 with a cam could get there too. Forget dual exhaust, not much to gain from that but weight.

3.1 and 3400 aren't the same bore


245 could be done on stock heads with headers and a good tune.. that's only 208 @ the wheels with a 5 speed. Most stock 3400 5 speed swaps are just under 200 with stock logs, a CAI and a decent tune.

[IsaacHayes]

Haha good catch. But yeah 3400 heads will fit on 3.1 bore fine... hahah. I must be asleep today. Edited and fixed!!

[1988GTU]

3.1 is same bore as 3400. So yes to 3400 heads. 3500 heads however will only work with 3400 or larger bore.

245, nope, not without cam and compression like others said. And even then it might be hard to get there.

3400/3500 hybrid with cam/etc yes that's possible and even more.

EDIT: modded 3400 with a cam could get there too. Forget dual exhaust, not much to gain from that but weight..

3.1 and 3400 aren't the same bore


245 could be done on stock heads with headers and a good tune.. that's only 208 @ the wheels with a 5 speed. Most stock 3400 5 speed swaps are just under 200 with stock logs, a CAI and a decent tune.

I thought that the 3400 valves would hit the 3.1 wall or not be within spec. Either way, not worth the hassle since the 3.1 is flat tappet and the oiling system isn't that great. Plus, what about using the 3400 roller rockers, isn't that going to be a problem? So you'd have to probably swap the stamped rockers onto those heads right?