10:1 is still too high for 93 octane. We always place SCR at 9.3:1 to allow for a "bad batch" (gas) or 91 (93 not available in ALL places).
The Icon forgings (FKA Keith Black) are quite good for the price. They offer a "dished" piston for 400. Unfortunately, the dish isn't quite "big" enough to get the compression all the way "down". With the 72 CC heads (advertised by Pontiac at 10.75:1), the SCR is 9.9:1. The head of the piston is thick enough to enlarge the dish to the necessary size.
The Speed Pro L2262F-xxx is a very good forging as well. A bit heavier than the Icon, but perhaps the TOUGHEST piston available. Plenty of "meat" in the head to turn a "simple dish" (3" in diameter, .100" deep will do the trick). The dish can also be milled in a "D" shape to mirror the chamber shape. This costs more to machine, but takes full advantage of the quench pad and chamber shape.
Since you're new to Pontiacs, I have two "pearls of wisdom". CHANGE THE RODS! Use a good forging and dump the cast rods. There are several suppiers and a few different configurations. The RPM 5140 ("Tomahawk") rod is the most economical at about $250-275 a set. The Eagle H-beam is the best-priced "premium" rod at just under $500 for a set. ANY forged rod (except the '50s-'60s production "rubber rods") is better than ANY cast rod.
The other "pearl" is to get Jim Hand's "How to Build Max-performance Pontiac V8s" published by SA Designs. This is the only current study of the ol' Injun available. Even if it isn't an exact "match" to your performance goals, there is a TON of relatively new information and a "history" chapter to get you "up to speed" on the "quirks" of the Pontiac. As a Chevy-oriented builder, no doubt you've heard a WHOLE LOT about the Pontiac, most of it based strictly on "myth and superstition". Contrary to "popular" belief, the Pontiac was the most sophisticated engine GM made during the muscle car era. It took Hemi to "knock it off the top" as the world's "premier" race engine. Chevy never managed that position.
