I got into this debate with a friend of mine.
PP LS1 StageII VS PP 5.3 Stage II

Which would make more power on the same motor??

 

The 5.3s would make a little more power due to the higher CR. That's the only difference between the heads, I believe.

 

I agree with above.

The 5.7's with lower compression might allow a hair more P to V clearance on a factory short block?

 

so what is the test motor? that needs to be addressed. is it a 346 or a larger displacement? more needs to be outlined for any true results.

 

346cu, LT,TR224,lid,Ported TB and MAF ends.

 

As said above, if both the 5.7 and the 5.3 heads are milled the same amount, the 5.3s will have higher compression and make more power, assuming that the higher compression does not cause KR.

Shawn

 

also the 5.3's can attain a higher cr without being milled which is a plus for pv clearance.

 

I hear that compression does not make that much more power, maybe a few more hp's but under 5, if you can get a better deal for 5.7's I would get them, you dont have to worry about p to v with the tr224 cam. What makes you want the patriots, a few guys are lossing power putting them on and switching to tea's, maybee look a few posts reciently

 

they are two different beasts...two different combustion chambers, valve sizes & compression ratios...i would say if they were both milled to the same compression ratio that the ls6 would fair a hair and i do mean a hair better only due to the valve sizes.

lata
Bill

 

I sure hope those 5.3 stage 2 Patriot's are gonna make the power everyone says they are. I'm planning on putting them on this week. I hope I'm not making a mistake.

 

im thinkin s3 ls6 heads so disreguard my comments other than combustion nchamber...but i think that would have to be negledgible.