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View Full Version : Intake Manifold - impact on performance?



Murphy
07-19-2004, 10:50 AM
When I rebuilt my SBC, I decided to use a stock cast iron high-rise dual-plane manifold. This is the manifold most of the aftermarket models were designed after, and there are some good reasons to use cast... less corrosion, cooler, more stable, etc. Originally the engine had an Edelbrock RPM Performer manifold. After the conversion, I lost about 400 rpm. I used to get up to 5200, now can only get up to 4800. I've made other changes too... went from a 3-blade Cleaver to a 4-blade Hydromotive Quad-IV, so it could be a number of things. Main question... how much does the manifold have to do with overall RPM and is it possible I would get anything back by going aftermarket? Any recommendations?

Murph

MOP
07-19-2004, 11:19 AM
Rob there are some far more knowledgable up here, but I did do a lot of asking and spent time on manufacturers sites. The Performer is a pretty decent manifold on our SB's, there is a lot to do with RPM range and where you want to develope the torque each design differs. There are some GM iron manifolds that do as good as some after markets. There is even a manifold swap site, it takes a bunch of time to look all the info over. Swap site below!

http://www.victorylibrary.com/wwwboard/index3.html

Phil

GKricheldorf
07-19-2004, 12:35 PM
Is it safe to assume that you are using the same carb on each manifold? If not are they rated to the same CFM?