Thanks, hotrod Lincoln, there's what I was looking for. So if the pistons are already high up the block then I would have to cut the pistons so much that I'd not have enough upper ring land. At that point I would have to buy custom pistons or rods which would negate the whole point of the low-buck crank swaap.

Would have gone and done some figuring but the motors are outside and at 15 degrees and 30+mph wind my enthusiasm for motor teardown and measuring was nil.

Guess I'll build my E85 motor with the 307 pistons and spend my time in the head area. Thinking I will use my small chamber 194 head to start the CR off a bit higher , then play with it from there.

Thanks again!