Thread: Head Milling

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Does anyone know how much I can "Safely" mill 049 or 781 BBC heads. I want to raise the CR on my .060 over 454 and I dont really want to change pistons to domed pistons. The motor is going into my 79 fleetside truck and is not a daily driver.

The other option is to deck the block, this also raises compression ratio by reducing deck height.

Either way, you'll have to cut the mating surface of the intake manifold also to make it line up. Your machinist will have a chart that tells him how much to take off.

It depends what you want to be at with your C/R, but likely you wont be able to raise it enough with those heads if you're using flat tops. Im building a 505, and using flat tops....with a 0 deck block and 100 cc chambers, I'll be at 10.2/1.... Your chambers are likely around 118/122 cc's, milling the heads 6 or 7 thousanths gains about 1cc. See what I mean? Go for a small chamber head is you want to leave the same pistons. 215's maybe or 290's. As far as cutting the intake, I once had a set of heads flat milled 45 thousanths, and the intake still fit OK....barely. It depends on the heads and intake. John