Just a little intake info for you guys based on my experience : Disclaimer ! I m by no means an expert or have any idea what I am talking about but here goes, many years ago we tried an intake swap on one of my 340s while on the dyno.. a brand new out of the box Victor 340 was 13 hp better than the gasket matched Strip Dominator, a few years ago before the chaos I spoke to Ryan J about switching from a Victor to an Indy 360-1 on my 363 he said there wouldn't be enough difference to warrant the swap. also my present stroker 408 with 4.10s 60fts the same as my 363 ( 30 0ver 360 5.9 block W2 heads ) did with 4.88s mainly due to 52 more pounds of torque over my 363. I have an Indy 360-1 set up ( heads and intake ) on my present 408 it must be an efficient manifold two years ago we milled one inch off the top so I could accommodate a different plate style throttle stop , well I lost 3 mph it didn't`t work out so I put on a one inch Super /Sucker and got about 1 1/2 mph back installed a one inch open and got the full 3 mph back. Based on my 6 different small block combos over the years an open plenum intake was always better than even a highly modified dual plane ( LD340 ) but then again these are race only.