Thread: 6 inch rod 357CID SBC

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gpzilla, what is the piston crown configuration, dished or flat. If dished, how many cc's? If flat, how many valve reliefs?

I'm trying to figure your ACTUAL static c.r., 'cause flat-tops with 4 cc's of valve reliefs, 58 cc chambers and 0.040" squish is gonna put it at 11.3:1

Same combination with 10 cc's of piston dish will put it at 10.48:1, so if you're using flat-tops, you're kidding yourself.

Just curious, did you consider the 12558060 Vortec heads? The reason I'm asking is because Lunati taught you to use a 305 short block with 305 heads, not a 350 short block with 305 heads.

The Vortecs are available from Scoggin-Dickey under part number SD8060RAGP all set up for 0.600" valve lift and complete with valves, springs, retainers, keepers and guide plates for $366.47 each. I'll bet you've got more than that invested in your 305 heads and the Vortecs will outflow them and they have a more efficient combustion chamber.

Posted by the dr...
" keep bumping the timing till you hear it ping then back it off 2 degrees...."

While I agree with the dr to a point, I would argue that detonation may have begun 3 or 4 degrees before you could actually hear it.

Posted by gpzilla...
"makes about 430hp according to Al's Custom Engines"

I'm not disputing Al's claim, but don't you think he's gonna tell you what you want to hear in order to justify all the money he's extracted from you. Have you had the motor on a dyno?