I was running a flat top piston in my 493" RB, and with the 76cc chambers in the Indy EZ heads it was near 12.2 to 1 compression. I enjoyed the nearly 7 years I had it on the street. I always burned 101 octane unleaded fuel through it, which was available locally 24/7 at the pump.

I pulled the valve covers for routine inspection, and found bits of the rocker arm bearing cages laying in the heads. I posted that story here a few months back. Turns out valve train harmonics from my hydraulic roller cam and some weak valve springs beat up my exhaust rockers, cracked 3 valve seats and compromised all my valve train parts.

I tore into the motor. In consultation with Dwayne Porter, I upgraded to a mechanical roller, replaced the entire valve train and had him freshen up and repair the heads. Great man to work with by the way!

While it was out, I bit the bullet and dropped the compression to a milder 10.25 to 1 compression, so I could run common 91 octane pump premium. Dwayne was instrumental in helping me spec out the pistons to get the compression where I wanted it.

No one made an off the shelf piston for my combo, so I contacted Ross. They made my previous set, and had the Job Card on file. I gave them the info Dwayne calculated and paid my money.

These 514 gram beauties showed up the other day, and I dropped them off at my local builder. Only recently had I seen a few pictures of what big block Mopar high-quench, reverse-dome pistons look like, so I've attached a few here for your viewing pleasure. I had the skirts coated to reduce friction.