From 4.15 stroke x 4.500 bore and 528 cubes, new combo is 4.315 stroke and 4.5043 bore for 550 cubes. 6.86 long Molner rods with 2.2 rod bearings replace the 6.965 long h beams i had, which allowed the offset grind to 4.315. Same pistons, but they were coated by line2line to take up the .0043 increase in bore to clean up the cylinders. The heads were cut a total of .040+ to get them straight again and get the chambers down to 62 to 63 cc. I had originally ordered these heads cut to 62cc but i strongly doubt it was ever done as they were measured at the shop and came up 67cc. So much for trusting what you are sold! So all these years i had a lot less compression than i thought. The added cubes and .040+ cut will bring it up about 1.2 points. Same heads, 440-1 ported with 2.30x1.78 valves, 3x intake, 284/296/114 duration cam with .870 gross intake lift and about .810 exhaust. The intake flow is 399 at .800 lift. Exhaust is 300 at .800. So the changes from the old combo to new are 22 more cubes and about 1.2 compression ratio change bringing it up to 15/1. I am looking for about 30hp. Realistic?
I am stuck curently waiting on cometic .027 thick gaskets, said to ship 7/1😒