The early '88 cars had a smalled OD crank snout (same as the 84-87 cars) and they changed it to a larger diameter in late 88 or 89. I found out as I got light aluminum pulleys from Unorthodox and got the wrong one first for my '88 EP/FP car. Because of the ID of the pulley, they are not interchangable.

The stock pulleys are solid with no isolated damper so a lighter weight balanced pulley should be no problem. I was told that the stock Honda engine was so well balanced to begin with that it needed not isolating damper and therefore a good aftermarket one should be fine and mucho lighter. My car has not fired yet but I intend to see 9,000-9,500 rpm, much higher than an IT car would.