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I agree that they do not take much to get them going, but it seems that good compression is crucial in achieving it. Selecting cams and bolting on intakes and heads only works in fantasy land unless the motor had zero deck pistons to start with. My first builder just put in the pistons cleaned the deck and bolted on monstrous 906 open chambers...and gave me a motor that would not hold a tune to save its life.



It takes more than a zero deck piston to get compression in a stock stroke 383 , the small bore is the killer. Doing the math on factory built 383's you BARELY get 9.3 compression out of a CLAIMED 10.0 factory spec , the pistons have to be poking out of the deck .020 AND the heads cut down to 79.5 vs the as delivered 90-92 cc. or you have to stick a 10cc - 12 cc dome on the piston which gets in the way of proper flame travel .

I wish KB made a step head piston for the 383 like they do the 440 and 400 instead of that POS KB162 , that would go a LONG way toward helping the 383 builder .





With the second rebuild I paid very close attention to the #'s with the builder and he lamented that the piston choice was not the best. However, since they were in and in great shape he felt he could make them work. I don't have the numbers in front of me as to how much he took off the deck and how much he milled the heads, but I do know that him and I both took the time to make darn sure I was over 9:1 for compression. Consider it lessons learned...it seems like the manufacturers don't give a hoot about REAL 383's IMO.

How about the KB400's? What's your take on those? I've heard they are a better match for this issue, but have not had a chance to use them.

'73 GK6 Challenger Rallye - 340 4-Speed