BORE SHROUDING TEST: 4.03" vs 3.91" Edelbrock RPM Heads Really Fit a 318? Project Mission Impossible

Illahe said
FWIW: NASCAR tested low compression in the Truck Series years ago. I believe the Ram was running W5 Cylinder Heads.

"Both employ carbureted 358-cubic-inch pushrod V-8s, but in presaging Winston Cup rules, truck compression ratios are limited to 9.5:1, slicing 60 horsepower from Cup cars' 720."

I thought it was only 9.0-1.
Does t matter actually since the cam sizes they run at super speed ways are monstrous and could really wake up from a sweet 13.0-1 or high ratio completely releasing the beast.