Building a 360 with ported and polished 587 J 202 heads. It has a comp 20-230-4 236/242@.050/110CL/.502/.511 mechanical-Ross 10.4CR/150shot N0S,780 holley,auto,etc. Getting ready to bolt on the Eddy RPM Airgap intake which has smaller port holes by about 1/8". Eddy tech says Don't port match, you will loose velocity coming out of the intake. What say you?

Myself I prefer a dead on match though I know I am not up to date on the "reversion" factor and how it will affect torque/horsepower

thanks RapidRobert, I feel the same way even if I just blend up about a 1/2"

Seperate from the reversion factor I'd sure think that a sudden increase in port dimentions would drastically slow the velocity as opposed to a gradual transition especially just a 1/2" one like you have in mind. What did they explain for the reason why they oppose

I think i would leave it alone. It can be very difficult to get the ports truly matched, especially with a dual plane. With a single plane , at least you have the benefit of being able to peer down through the plenum and shift the intake around until it is aligned with the ports. To get a precise match, a little more is involved than just laying the gasket on, scribing it and grinding. IMO, better to leave the intake a little small.

they just said it would lose velocity and they would recommend to leave it alone. You thinking I should blend up further? I have always done major port matches with 3" blends, but a little confused with the recommendation from Eddy tech. I may give them a call again and get a second opinion.