487 heads

[Paulsky]

Hi guys, I have a stock 307 motor with 487 heads, I'm putting on a 600cfm edelbrock carb, edelbrock manifold, summit 1103 cam and a set of block hugger headers, im going to port the head but would like to know how much I can skim off off the head with stock pistons to bump up the compression, our fuel over here is 95 octane. I'm in South Africa so performance parts aren't that freely available.

[Marv D]

Flat milling you take about 0.009 -0.010" off for every CC you want to remove from the chamber. It depends on the chamber shape and size to begin with but that will get you close. Without knowing what deck height, gasket thickness, piston volume and chamber you have now,,, resulting compression would be a crap shoot.

The 3973487 head was a 75cc head from the factory. On a 307 in totally untouched form you would barely have 8:1 compression with a 75cc head. You need 62-64cc to get above 9:1

The small bore is killing you. Besides, that 3.875 bore and a head with a 2.02 Intake valva will contact the edge of the bore if you get crazy with lift. So be cautious in what you do there.

[Paulsky]

Thanks very much

[68Gold/white]

The 487 head is a 350 or 400 small block head.

They are pretty good heads for a 350 or 400. In the days before all the aftermarket stuff and factory vortec stuff was available, 487's were prized heads for a good running street build. Still a good head, but all the folks w/ $$$ and in the know wouldn't have them...

Might be worth your effort to find a 350, I doubt there's a small block 400 in South Africa...LOL

If you use those heads, be cautious w/ any grinding. You can lose more potential performance than you can gain if you grind in the wrong areas, and too much. Best approach is to obtain sand paper rolls (called cartridge rolls also), take sharp edges off on short side radius, and gently blend rest of port up to the seat. This will help, and not hinder anything. Not just an opinion...