I am considering changing the heads and cam on my HP 500's. I am very interested in the AFR 315 cnc heads with a Crane 741 cam. I would like some advice from the engine experts out there. Do you think the 315 cnc is the right head or the 305 with cnc'd chambers. I spend most of the time running 3500-4000 rpm. I am looking for alot of mid range torque and a solid 600 HP. Thanks in advance for the advice. Jeff

Jeff:
Your choices for heads and cam are excellent companies and great parts. The problem is there is no way your going to see 600HP out of your HP500 with just those changes.To ge a HP500 up to 600HP the easiest and most cost effective way is to use a Whipple supercharger with Dustin's reprogram on your ECM. The other question is do you have an XZ or XR drive to take the extra power? Consider these thoughts before you get yourself in a one way trap.
Raylar

Pro Charger

change the heads to 305 intake runner and put a hyd rollersomething around 242.int 248.exh at .050 lobe cnt on 112. and change the comp ratio to 9.5 to 9.7 and install a 950 holley and msd ingition and the motor should make around 615hp. and reliable,

Raylar,
Thanks for the advice.
These are 1998 HP 500 carb motors, when I am finished with the upgrade I want them to look stock, so no supercharger.
CMS Racing,
I will have the heads milled to 114cc combustion chamber, AFR says this is worth 1/2 a compression point, so that should be approx. 9.25 to 1. How is the idle and water reversion with the cam you described?

idle is good with the 950 holley on top the tail pipes will have to be altered to work . I use IMCO to change all my pipes around. they will work on anybodies tail pipes for mods. best to add on and go throught the transom .but addind dumps and restricting water flow entering the exhaust to (2) 3/16 holes should work. I have done a lot of 500hp upgrades at my shop and the combo should work good for you. get the comb. chambers to 110. cc and 0 deck the block.to get the comp. up

I also have a pair of carb HP500's (1999) They were just rebuilt but I left them bone stock. I was just wondering if there is any advantage in converting to MSD ignition. Fuel economy, HP or torque?

CMS Racing,
Do you think the "741" cam is too small? I will spend most of the time in the 3500-4000 rpm range with little wot time. Jeff

Stroke it to 540 while you are at it.

Wags382,
Are you going to upgrade the exhaust manifolds?
Are you planning on running @ 5500 RPM +?
Bob