LT4 hot cam on IROC-350
 

Has anyone installed an LT4 hotcam on an L98 TPI? If so, what rockers, pushrods, timing chain, distributor, lifters, and computer chip do you need to have the setup work like a charm?? My car is a 1990 speed density L98 with stock internals and all boltons, but will be adding ZZ4 heads soon, so need to hype it up some more. Let me know what you know---Thanks to all who help me out with this situation. ----Pablo.

Forward this to pablo.ledezma@lmco.com
and chevyracing@msn.com

I'll check the post frequently during the day---Thanks.

Mechanically it will all bolt together. However, that cam will out run your TPI manifold and the ZZ4 heads. The ZZ4 heads are seriously outdated and for just a little more, you could get some AFR's or Edelbrock heads. A better suggestion might be to get the ZZ4 camshaft instead, or if you're intent on the LT4 HOT cam get some better flowing heads and TPI manifold as well. It's better to have an engine where all the components work together than to have a high winding cam in an engine that can't take advantage of it.

Intake upgrade too
 

I was planning on putting the LT1 intake on the Iroc as well. I have it already, just haven't taken it to the machine shop to get the distributor hole drilled. What are the details, details. I am in the midst of either getting an LT4 cam or the ZZ4. Just need to figure out what is my best bet. Thanks===Pablo.

zz4 heads are l98 heads :) just so ya dont waste ur money

damn ya beat me to it.

like he said L98's and ZZ4 heads are identical, two names for the same thing.

the hot cam will go right in, but you need to upgrade your valve springs, specially if you have a lotta miles on your motor. your intake and heads are gonna choke it off a bit though.

Performance >>>>>>>>
 

Jesus gentlemen,

We're talking performance just by saving 35-40 lbs in wieght, not to mention the heat dissapation with Al heads. Yea, L98=ZZ4, but that has to be better than Fe heads. I can always sell them to a bud of mine once I decide to get AFR's, I've got the nitrous injection giving me a smile from ear to ear anyways. I just want a little more performance on stock power. By the way, what roller rockers will fit under the stock valve covers and give me the proper performance with the ZZ4 cam I have decided to use afterall? What pushrods? I need pushrod and rocker part numbers to complete my setup---plus timing chain--double roller.

I believe GM actually sells a complete HOT cam upgrade kit which has everything you need.

Re: Performance >>>>>>>>
 

I used CompCam 1.6 roller-tiped Magnums, not full-rollers. I, personally, prefer steel to aluminum so it was a good compromise as far as price, performance and fit under stock covers.

As far as pushrods, I think you should check what length need w/an adjustable pushrod tool and order accordingly. Put "Valve train geometry" in to "search" and you'll get a lot of useful info on the subject.