Im currently looking for cylinder heads for my car...

I was going to get the 5.3 Stg2 heads then I found out about the good deal on 98style stg2 perimeter bolt heads....

I know the size of the combustion chamber on the 5.3 raises compression about half a point over the stock LS1 heads.

How much HP diffrence would the compression diffrence actually amount to.

If im only losing around 5-10rwhp I can spend the diffrence in price on some other parts to make up for it.

Another plus is not having to change the valve covers or worry about the coilpacks.

 

I dont think you will lose any power between the 2. have them mill the 98 heads alittle and they will make the same power

 

under 5 hp gain and like ne14 said you can get the 5.7 heads milled a bit and make most of the compression up.

 

Go with the 5.7's. I didn't realize that they were available for my 98. I'm very happy with my PP 5.3's though. For the money the 5.7's can't be beat.

 

As mentioned, the 5.7L perimeter-bolt heads are hard to beat for the price! If you're running a 224/224 cam or smaller, you could mill the heads .030" to bring the compression up to right at 10.5:1. However, this will limit your ability to upgrade to a larger camshaft in the future without having to cut valve reliefs in your pistons.

Let me know if you have any other questions or if you'd like to get a set of Patriot cylinder heads on order.

Trevor
Texas Speed & Performance

 

Trevor, I have some PP 5.7s milled .050 (not installed yet). Do you forsee any PV issues w/the cam in my sig? Also, how much compression would this give me? I was hoping for 11:1. thanks

 

Milling a set of 5.7L heads should put you around 10.8:1 CR. I have not measured p-to-v clearance with the cam that you have listed, so I would recommend that you measure the clearance when the heads are installed. I would expect you to be okay, but the only sure way to know is to take measurements once they're installed.

Let me know if you have any other questions.

Trevor
Texas Speed & Performance