I got a stock L-98 5.7L '89 Iroc.
I am in the process of upgrading with some bolt-on stuff...

LT-4 Hotcam Kit with new springs & 1.6 roller rockers
1-3/4" SLP Headers
Hi-Flow Cat
3" Borla Cat-back system
Edelbrock Hi-Flow TPI base & Runners
5 angle valve job with some mild port clean-up...

maybe:
having the plenum ported
adjustable fuel pressure regulator
chip
bigger throttle body...

Has anybody used this combination...??...What kind of horsepower should I expect...???

Also. I saw some chatter on these boards about the "Pressed in" rocker retainer studs..?? Not planning on racing this when I get er done, but want to take care of a possible problem while I got the engine apart....

Thanks,
Larry

 

Screw in studs only :-)

Pull some studs out otherwise and I will laugh and say I told u so.

Its not that much to do and saves lots of aggravation.

The LT$ hotcam TPI has been beat to death here do some searching.

WIth some tuning, they run well, I had one once.

later
Jeremy

 

Agreed, use screw-in rocker studs. They are cheap insurance because it really doesn't take much to pull out the pressed in studs. Screw-in studs won't pull out. If you stay with pressed studs, and happen to pull one out, its a nightmare to fix without pulling the head off. Take the heads off, take them to a machine shop, and have them machined for screw-in studs, buy a set of ARP studs, and call it a day.

 

You'd be better off buying a new set of heads with a cam that big. Our stock heads suck, and while you will have more power, it wont run as well as an engine with that cam should.
I had to make my own custom chips for my LT4 hot cam install. Just buying a Hypertech or whatever generic chip wont cut it.

 

I got my PROM from PCMforLess.com- excellent choice, best bang for the buck so far! Definitely port that plenum. I spent 5 hours on mine as I"d never done any porting before. You can send yours in and have a basic port done for less than a hundred bucks I think, or there's this guy Mike that does corvette TPI MEGA-porting- His stuff will give the approximate same flow and power increase as the Holly stealth ram.

I was just in the process of deciding to refresh my 88 L98 block but have decided, due to the awful heads we have, to just go ahead and do a ZZ4 short block build.
Nitro