The 305 heads are the exact casting number that Lunati used in their horsepower tests. I performed the exact same machining process on those heads that Lunati did with the exception of 1.60 exhaust valves. The valves are Manley RaceFlow undercut valves. Check out the link to see what Lunati taught me:

http://www.hioutput.com/tech/343hp/343hp.html

I am using an Edelbrock RPM performer intake, and a Mallory Unilite Photocell Distributor, with MSD 6AL, MSD variable timing module, and Blaster coil.

Sure I could have shelled out a couple grand for expensive aluminum heads. I liked the tip about the angle machining of the pistons. I hadn't heard that one. I am running 10.5:1 compression and have .040 head clearance at TDC with the gaskets installed.

I zero-degreed the cam to be sure it was on the mark. With the Edelbrock gear drive it was, had I used a chain, I would have needed to adjust it.

Here's the cam I am running -

Crane HR-276-2S-12 IG

intake @ 325 is .488 with 1.5 rockers
exhaust @ 339 is .509

Cam timing is:

.050 @ 0 BTDC closes @ 34 ABDC max @ 107 ATDC DUR 214
open @ 48 BBDC closes @ 6 BTDC max @ 117 BTDC DUR 222


So back to the original two questions.....

Edelbrock 750 or Speed Demon 750 which is going to give me better accelleration?

What's the max ignition timing I can run on this engine, with 28 degrees built into the distributor? Or should I just set it at 36 degrees at 3000 RPM and dial in the other 6 degrees and see if it makes a difference or causes detonation?


Could I benefit from swapping out the 1.5:1 rockers with 1.6:1 rockers? I know this changes roller to valve stem geometry, but it can't be by that much. What kind of hp gain could this make if any? Perhaps several more ponies? I have enough valve clearance to facilitate this swap without having to re-check with clay.