It is an ls based engine.

Op, i ran 11.4 on 7.5 psi with my setup. My engine is a forged 347. A 370 would get you in the 11s easily. Hell it would take you deep in the 10 easily. Unless you just want a 408, a 370 will do the job and be cheaper.

 

That's what I'm thinking, it's proving to be a hard choice lol

 

317 heads will be fine, maybe a port an polish while there off, bigger heads would be a huge increase in power, but they will work with a 408. like i said I'm kinda in your boat and I'm leaning toward a 370 build.

 

370 stock crank

 

I can see what he's saying, but those are generalized concepts there -- all of which rely on the choice of parts...

With the 408 in BRT, I made more power (with more boost) than the op is looking for in a build that was together for years and parts still look brand new.

 

Stock 317s are not ideal for a 408 (370 there's more wiggle room), but a worked set will be fine. A set of larger volume heads would be perfect for a max effort, but not necessary.

 

I'm not using the stock crank lol, I got money's saved for a crank. Hell a 10 second truck is plenty fast and if a 370 can do that with 15 psi, I'll do that

 

^^^u said cheapest way

 

Honestly For 10's or 11's at less than 5000lbs I wouldn't even build a engine a good 04 up lq4 with cam, springs arp studs and ls9 head gaskets is more than enough. A nice forged 370 with a factory crank would be the max I would do. JMO

 

The lq4 I have needs to be rebuilt and I already have a hand full of parts lol. It's looking like it's gonna come down to a 370 with 317 heads and a proflo intake on 10 to 15 psi. HP guess?