UltraZLS1

iTrader: (13)

Ill be getting some patriot 5.7 perimeter bolt heads in the near future.

I was wondering which valve size would be best in my car.

2.02/1.57 or 2.055/1.60

pro's and cons of each? power differences?
Im on stock cubes/224 cam/full bolt on/m6

thanks a lot

orangeapeel

iTrader: (18)

Are you getting the preimeter bolt heads from Patriot?
Are they ported/milled?

Those valves being oversized may or may not help you.
Having bigger valves isn't always the answer really. It also has to do with port volumes, style of head, application it will be run on and lots of other technical stuff that I have a hard time understanding myself.

UltraZLS1

iTrader: (13)

no porting or milling. they are patriot

orangeapeel

iTrader: (18)

I thought that they would be. I assume that you are getting them due to the coil pack brackets and valve covers that you already have on your 98?

98Z28CobraKiller

iTrader: (17)

I would switch to the newer style. THat is what I did. I picked up some new valve covers from eBay for under $100 for the pair brand new. A guy bought a crate motor from GM and was making it a race motor with bigger vavle covers. I think that I got the different brackets from SPDC for like $80 something. The old coils will bolt right up. Hint: Have SPDC send you new bolts to work with the brackets. For under $200 you can upgrade and if you ever want to swap heads again, your selection wont be as limited.

Also, spring for better heads. Some AFR 205's or the small ET's should be what you buy or else you will be buying them again.

Good luck.

PREDATOR-Z

PP perimeter heads are ported and stage II is what you should get. (2.02)

UltraZLS1

iTrader: (13)

Come to find out they will mill them or make them any cc chamber I would like for free.

So....Should I have them changed?

What cc? Any milling?

It is a daily driver, I just want the most streetable power I can get out of these heads.

Ill be using stock head gaskets

PREDATOR-Z

I would say 62 cc will get you close to 11.0:1 (10.9x)

UltraZLS1

iTrader: (13)

So my best bet would be to order them with 62cc chambers....no milling?

PREDATOR-Z

They are 66 cc so yeah they would have to be milled to be 62cc