502 hp gains
 

i have 502's with stock rect port heads 630 lift hyd. roller,crane victor intake, 830 holley, stelling headers and stock 8:75 compression. I am upgrading to 315 cnc AFR aluminum heads and 10 to 1 compression. What hp will i get think in 520 range now. This heads flow huge numbers for the small intake runner.
Again thanks in advance.

Your cam will certainly appreciate the higher compression ratio.

It will reward you with a good kick in the pants.

Careful on the octane...

Head choice!
 

Greg(Bad to the Bone),

Are you running those Crane 139741 hyd roller cams?---Just curious. With those AFR heads you bought I think your engines are going to come ALIVE! Especially if you are going from stock GM UNPORTED heads to the AFR CNC PORTED heads! Those 315cc AFR's are even smaller than your stock GM heads which I think have something like a 325cc intake runner volume. And with the AFR's being that size and yet being CNC PORTED those engines are going to act like cpmpletely different animals! That means you'll see some pretty nice torque gains as well as HP. I would think you should see close to an 80hp (at least) increase per engine. Of course this is just a guess, but I'm having a little fun with it here. BUT....BE WARE!----At 10:1 cr you had better make sure that you're puting some GOOD fuel with the octane rating that you THINK you're puting in that thing. Some gas stations don't always have the octane rating that is being advertised----it can be bad gas for one reason or another. Awsome choice on the heads though----dang I'm jealous! ;)

head upgrade
 

Kaama
i am actually running the 951 so i really need the compression.
The AFR flow some great numbers 380 at 600 with the smaller
runner sould make big difference. By the way your trans are
holding out great. greg

Greg,

Glad to hear it on the trannys! Like I told you, I think they were modified with additional clutch plates in them, but I really don't know for sure----just glad you're happy with them and that they're holding up and working out for you! :)

380cfm at .600" is VERY good, but it's actually the lower lift flow numbers that are really going to make a BIG difference in flow I think as well. The lower lift numbers on those CNC'd AFR's are what's really going to make the difference! I'm anxious to hear how your boat runs with them!