98Zheadsncam

iTrader: (26)

Ok guys, I'm debating about whether or not to get a 415 ly6 shortblock, and throw it in my car with my prc 5.3 heads and a big cam. I'm totally aware that these heads are less than adequate for this amount of displacement, but could I at least get by with them for the time being, and still make good power? I was going to get a custom spec'd cam, something in the 250-260 duration, around .650 lift. It's an m6, so i'm not worried about the driveability. Of course, when I have more money, I'll be upgrading to some tea heads or similar. But, in the mean time, what do y'all think about just using the 5.3 heads?

Ellesone

You can get by with them but dont waste your money on a cam, save it for new heads
You can get by with any smaller head ... might be real peppy down low but as you know will choke it out up top... save the cam money for now for a set of ported 243's or an LS3 top end

98Zheadsncam

iTrader: (26)

Cool, thanks for the input!

litle88

iTrader: (20)

Might want to check what your compression ratio too, what are you bore and cc sizes?

batboy

iTrader: (6)

Are we talking about ported 5.3 heads with bigger valves or just stock 5.3 heads? If they are stock, forget it. Even ported ones will choke a stroker, but you could get by temporarily. Compression ratio should be considered like litle88 said, because 5.3 heads have 59cc compression chambers. That might be too high of a CR for a stroker unless you have dished pistons.

98Zheadsncam

iTrader: (26)

These are the PRC stage 2.5 5.3 heads. I didn't have them milled, so 63cc chambers. Valves are 2.02 intake, 1.575 exhaust. 10:7 compression on the stock shortblock, I believe.

speedtigger

iTrader: (16)

Those heads flow 300+ cfm. I am thinking it ought to run pretty strong.

98Zheadsncam

iTrader: (26)

This block i'm looking at is on ebay. The builder offers a 4.030, 4.065, or 4.070 bore, with a 4.000" stroke. I was thinking the 4.065 bore. I'd think it would make close to 700hp with the right heads and cam down the road.

mercccc

I went 126 mph with those heads with a stock bottom end 6.2. I remember seeing a few 370/383 ci, heavy cars going mid 10's around 130 mph with larger cams then what I was running. There is better out there but if you allready have them give it a shot.

98Zheadsncam

iTrader: (26)

That's what I was thinking...they couldn't hurt. Plus, it would allow me to sell my stock shortblock and get some extra cash for new heads. As I said earlier, I was thinking some TEA ls3 heads. Of course, then I couldn't use my fast 78. I just think anything less than a rectangle port would be wasting the c.i.'s.