I have some funds saved up and i'm looking to build up the iroc this winter. I want the best bang for the buck. Need direction. Heres the specs of the motor and what shes currently got and does.

GM Special Performance 5.7L (pt# 12356644)
Supposed specs from the rap sheet
300hp @ 5000rpm
369 lb/ft @ 3500rpm
Comp Ratio: 9.1 : 1
Bore x Stroke: 4.00" x 3.48"
Max rpm: 5700rpm

700R4 trans, Stock TPI setup, 3;70 posi(third set of gears, second rear end), hooker shorties with del. cat and flowmaster.
Went to the track this year ran around 87mph @ 14.7 Car gets good rubber shifting into second. think it eats the rear gears up.

I dont like all the wires and crap in the engine bay and its really dirty, think it would be cool to pull the motor and clean the bay out, and get a new setup in there that doesnt use the TPI mess and easier to work on and play with.

Now about the car, I'm looking to do something major to make her scoot. Roots blower? ls1 motor and trans? What is the best bang for the buck? id like to make HP and have a much higher top end.
Thanks in advance

 

 

What does this have to do with tranny/drivetrain?
This is more of a tech/general engine question....

That's a gorgeous car right there... First off, 300HP and you're doing a 14.7 @87mph, and you catch rubber in 2nd gear? What's wrong with this picture here?? Are you coasting for the last while at the quarter mile or what?

How much do you want to spend? Roots blower and LS1 are both wildly different approaches, with very different amounts of difficulty and results.

I'd just mod what you have now. A 350 with injection can run mid 12's and still be streetable (ask the guys in the TPI forum, i've seen some hot ones).
mini-ram, cam, heads, headers, etc. That's small dollars vs your other choices.

 

thank you sir and thanks for the reply.
I dont think the car has ANY top end. it just gets loud lol well you know what i mean.
It stays with LS1s up to 40-45 then they walk all over me. theres not much left after that speed.
I am willing to spend as much as the build takes, would like to see my options here and what approaches i could take at this.

 

Head over to the TPI board. I'd recommend if you have an injected engine now, stick with that. Unless you're going pure drag race, I wouldn't go to a carb.
Look at what other guys on that forum have done to speed up their roller 350 engines. I see many in the high 12's with streetable injected NA setups, that's plenty fast.

I can't remember any names off the top of my head though. 1987GTA I think is one... dyno don is another....

 

Got a similar question. I've seen a few links online for rear-ends. I'm building a 383 stroker with 400-500 hp and up as high as 600 ft/lb of tq. I'm building up the suspension as well to include tq arm, lca's panhard bar, sway bars, shocks, struts, springs, k-member, sub-frame connectors. My question comes in the rear-end, what aspects are most important to look for? Where should i focus most of my attention and money? I have z06 rims, and I want disc brakes instead of drum, other than that, I have no preferences. Money isn't the issue, but I don't want to over pay for parts I don't need.

 

Do a head and cam package to your 350 and switch to a stealth ram intake from holley. It's well known that the stock TPI intake chokes off power past 4600 rpm. I have a 350 with a small cam and head package and I run low 13s to high 12s depending on the tires I have. With just a head, cam and intake it would be no problem for you to make 400+hp at the crank and you could clean up your harnesses while you were at it and spend less than 2k.