[Jay S]

Someone on this board might know what the volume is on the head of those 428 pistons is so you would not have to cc it. I don’t have them in any of my speedpro or TRW books. Speedpro may have changed them on the later years and made the dish a bigger diameter. Seems like the later production runs had a 8.5 cc dish and 5 cc VR’s and the older pistons like yours are a 5 cc dish with just under 6 cc VR’s. Measure the dish dimensions and see which pistons you have. Then check the deck clearance.

The 6x-4s on that 428 is more of an 87 octane combo with either cam. I am guessing there is just under 2 points difference in octane requirements between the Crower 60243 and the 274XE. I would not consider either cam big enough to be a “crutch”. I would not do Rhoads if you have the Johnsons already.

I agree with FJ, figure the compression and pick the
cam.