Hi!
I am going to install following on tmy engine this winter:HSR,24lb inj,LT4 hotcam and i am thinking of have my stock L98 heads ported or do you think it is a waste of money.Thanks for any replay.

 

The Stealth Ram should support more air flow, so it stands to reason that larger port runners would be benficial. The more you can make the heads like LT1/4 heads in that application, the better. That may also include larger valves, if you're so inclined. The only thing I might do differently is to port and otherwise prepare the heads myself.

Your LT4 cam is going to require careful checking on stock heads for clearance between the valve spring retainers and stem seals. If will also require different springs, and should include the elimination of the valve rotators. The larger springs will require different spring caps and retainers. That will require that the spring seats get machined. The increased spring pressure and higher lifts will almost mandate that you remove the pressed studs and install screwed rocker studs.

Paying someone for the labor of serious head preparation and port work, including the valve bowls, can be less cost effective than replacement heads that are aleady offered with larger ports and valves, better springs, good seals, no valve rotators, and good screwed rocker studs. Check the prices of heads compared to labor in your area. By the time you purchase the new valves, springs, studs, retainers, and seals, new heads may be a bargain.

 

http://cgi.ebay.com/ebaymotors/New-P...QQcmdZViewItem

You could save money & time by buying them already prepped.

 

Ok Thanks for the replay!
I think i will go for these aluminium heads:combustin chamber
64cc
Exhaust
1,600" Rostfri

Intake
190cc
springs
High Performance, lift max 0,600"
valve guide tapped
3/8" gänga
130 psi @ 1,800" (Stängd)

Ventilstyrningar
Fosforbrons
320 psi @ 1,250" (open)

Intakevalve
2,020" Rostfri
They are about USD 1200.
Here in sweden

 

Get vortecs, put the 2.00 intake valves in and do a small pocket port. You can see flow of 240 at .500" doing just that. It would only cost a small fraction of a professional port job on a set of factory heads or a new set of aftermarket heads.

 

Get a larger cam than the lt4 hot too. I ran it for a year, not as big as people can think. I noticed zero lope after it was tuned. Gas mileage was the same as other repoted 350 tpi's with less cam. Go with a bigger cam. The GM 846 or CC306 is a good choice.

Some one on here (forget his name, Pablo?) had a LT1 that he only put a CC306 cam in. His friend also had a LT1 that had the LT4 intake, LT4 heads and LT4 hot cam. The CC306 cam beat him. It was a fairly lrge thread.

 

Ok thanks for the advice,but i have alredy got the cam and intake it is just the heads left.

 

Port the L98 heads yourself then. David Vizard goes over step by step what should be done to them in more than one of his books. There have been a few good threads too. Hopefully you have the aluminum vette heads.

 

There is a pair of trick flow head for sale here priced at $500.00

 

Will the vortec heads fit my stealthram intake?
Thanks for the replays.

 

Only if you bought the stealthram intake that bolts on to vortec style heads.

 

Those heads won't stay for sale for very long. They might already be gone.

 

Hi!
I have found a pair of ZZ4 alu heads here in sweden ,are they any good and will they fit my car?
Thanks

 

In stock form they are not very good, the intake ports flow around 200 cfm @ .500 valve lift.