[DanEC]

I think the book would be real interesting to you considering all that you're doing on the car. He has a pretty good description of each intake and test results (engine dyno) on several different configuration mules.

He said the RPM was probably the best all around and most versatile manifold for performance and finished in the top 3 single carb intakes on the 427 SO and 427 stroker motors. He noted about a soft spot down low but said it was most pronounced on the 410HP 428 CJ and not as much so on the more modified engines. He said port matching it boosted HP notably - but resulted in some loss of torque - but again this was most noted on a 390 stroker engine combo and he didn't mention it on the 427 engines. He made a point that this is a dual plane manifold but doesn't always behave like a typical dual plane manifold.

Just eyeballing the charts the RPM started exceeding 550 ft lbs of torque at about 3200 rpm (going up to just under 600 ft lbs at 5,000 but falling off slowly) while the Victor was kind of flat around 550 from about 3,800 until about 4,400 rpm and then started rising to just under 600 somewhere around 5,000. The RPM torque curve does look much broader and less peaky. It looks like the torque falls off slower past 5,000 with the RPM also.

From looking at this I don't think I would expect to pick up any additional torque with an RPM, but you probably won't lose any either (or much) and you should have a much broader torque curve.

I can try to scan a few pages of this later today.