(2)450 DP's vs (2)750 DP's

MomsDuster said
They didn’t have TSR’s. The holes were larger than that, so I tapped them and threw in the .098’s. Closest to the original size of the passage. And yes, the PVR’s are .038 and from the factory.

On a tunnel ram your TSR’s are probably .020 bigger than the need to be.

I start at .074 on single 4 stuff and usually go down from there.