My current specs are in my sig, but the basics are:
GM Goodwrench LM1 350
Weiand Stealth Intake
EdelBrock 750 carb
Comp Grind: 262XE Lift: .462''/.469'' RPM Range: 1300-5600

I am looking to make 450-500 hp at the crank, I'm gonna need drivetrain upgrades i know, but currently im just looking at engine parts: heads, cam, maybe pistons (want 10:1), roller rockers.

I was looking at:
AFR 210 competition heads- Flow 276/207 int/exh @ .500 lift
Comp Cam- Grind: 284 Lift: .507''/.510'' Duration: 284/296 Lift: 110 RPM Range: 2300-6500
Comp Pro Magnum 1.6 roller rockers

The pistons i havent looked at yet, but I want to make 10:1 compression with the 76cc AFR heads and I should probably get a 3000 stall i was looking at the 9.5 lockup from Pro-Built ( i just looked and the website seems to be down...)

One question will the 1.6 roller rockers give me a HP increase over the 1.52 and will they change the power band of the cam ?

Second with DD2000 the setup im looking at not counting the rockers is showing up at about 420hp with the 10:1 comp and 385 with 8.5:1, does this seem accurate

Finally parts and labor this looks like it will cost me at least $3500. for this price i can get a ZZ4 and i know a guy that will probably charge me about $300 to put it in.

Or I can buy a ZZ4 short block for $2300 and build it from there.

Last thing what would you consider a safe RPM to rev my current engine too and would the ZZ4 have a higher redline?

I guess im really just looking for opinions sorry for the long post and thanks.

 

Ok since no one answers my questions, maybe someone can tell me why no one answers

thanks

 

First off , that's a lot of questions

Umm, definately need new heads, cam, pistons. 76cc heads will be tough to get high compression out of right? Or I guess certain pistons can cure that

Higher lift rockers will create more power than 1.52 as long as the rest of your setup can match it, which I assume will. Not sure if it ups the powerband of the cam, that's a good question I'd like to know, but it will increase the lift of the cam.

 

I'm sure some of the resident experts will chime in, but, I think you should reconsider the 76 cc heads, with the cam and rocker combination it's going to be hard to get big enough domed pistons to get compression up that high without hitting the valves. there are some good flowing heads available out there that are in the 64cc range which will give you good compression without sacrificing cam lift choices. by the time you get the block decked and make a decision on the heads you should be able to order pistons to get the compression right where you want it. the bigger ratio rockers will increase the lift on the valves some and will increase the duration a TINY bit but not enough to make a difference, the biggest benifet to the larger ratio rockers is the lift increase, make sure you get some good steel roller rockers "don't get aluminum" they are primarily for race applications and won't hold up on a street car

 

Ok so if the 1.6 rockers increase lift but not duration then the power band should not be effected correct?

 

I just want to check to see if I did this math right

the cam I want is 0.507"/0.510" with 1.52 rockers
so with 1.6 rockers it would be roughly 0.534"/0.537"

and the rest of the specs wouldnt be change significantly correct?

 

You don't need that much head to make that little power. A XX4 (ordinary 350 short block) with the ordinary ZZ4 cam and a set of GM FastBurn heads makes 430 HP for example.

To get to that kind of power level, and have the engine survive for any legth of time doing it, the LM1 is not the right platform to start from. It has the crappiest rods there are, a cast crank, and dished pistons. About the only decent part is the block casting, in case it's one of the 4-bolt-main ones. Remember, it's a little like stock Vortec heads: it's a [b]replacement truck part intended for fleet owners/[b], not a "performance" part.

To get 10:1 compression you either have to use domed pistons (not th ebest idea) or mill the heads brutally. Those heads are set up for nitrous or blower use, and are not a good choice. You'll do better with 64cc heads and flat-top pistons and a Fel-Pro 1044 head gasket.

I would strongly urge you to get a better converter than that ACT. People seem to have more trouble with them than most, and none of the really fast cars are using them. With converters you get what you pay for, since the price is based on hours of labor more than anything else; all converters of a given diameter are definitely not all equal.

Lose the low-rise intake and put something better on it. Same goes for the carb: get a Holley or a Demon.

Nearly every piece you have is inadequate. You are looking to nearly double your power output, you can't just nuibble around the edges. You're talking about going away from a slightly modified street replacement truck engine to pretty much a hard-core racing one. It will require nearly every part to be different, especially the induction.

 

Ok well in that case, I am going to seriously consider building a 383, or at least a totally new 350, maybe I will just buy a ZZ4 and start there.

I figured the bottom end of the engine was pretty crappy.

This engine is definatly the worst thing i ever did to my car =\

btw what brand converter would you suggest?

 

Yank, Coan, PI

That engine isn't a bad thing to do, it just doesn't create alot of upgrade paths without taking it apart and throwing most of it away.

 

So what brand of Stall converter would you suggest?

 

 

ahh sorry i somehow read over that part, wasnt sure what it was