Flat top or domed pistons

I've tested it. Even at 15.5:1 on a 3.313 stroke with W2 heads I've never had an issue with flame travel. Never had to run more that 36 total on gas and I ran 40-42 on alcohol, which is well within normal timing.

And that was a big dome. I had a couple of used Pistons with those domes on them...but I used them up doing some development work when I went to the W5 stuff or I'd take a picture of the domes. They was big.

If you think about it, the small block Chrylser has about the best plug location you can get in a wedge head.

If you look real close, you can see the plus is almost in the top of the chamber, almost like a Hemi. That's why a big dome isn't a killer like most thin it would be. Even on the SBC stuff with a big dome I only had to run 2, maybe 3 degrees more total with a big dome over a flat top.

If you look at that super sexy domed piston you have and imagine where the plug would be...it's almost on top of the dome.

If that same dome were used on a SBC head (not talking about really cool 18 degree or SB2 stuff, just regular 23 degree heads) instead of the plug pointing down on the top of the dome, it would be pointing right at the side of the dome.

That's a big difference in plug location.

Run the gas ported, domed sexy Pistons. You won't regret it.