gumball...good question...my understanding is that a highrise offers a straighter shot for the air charge to enter the heads and cylinders making for more cylinder filling
therefore a tunnel ram should be better than a highrise which in turn should be better than a lowrise
rick..i dont have a reference that identifies that manifold...maybe someone else can help..
as best as i can measure, the carb mounting surface is about 2 3/4 inches above the front manifold/block interface on my 3955287 LS5 low rise manifold...mine is set up with a 3/8 heat insulator / gasket beneath the carb base and 3 gaskets at air horn...with a single gasket the bottm of the filter base binds against the carb...that exta 3/16 or so of the extra 2 gaskets provides adaquate clearance... no other spacer anywhere tho as i understand it , from the factory there was a spacer between the air horn and the filte base around 3/4 to 1 inch..on my set up that would really compress that air seal to the point of distortion i believe
anyone have a performer and performer RPM in the box that is easy to measure???
but then again, the general sure made a pretty ptotent engine (LS6) with a lowrise rect port manifold #3977609 so i sure dont know the answer... but that manifold sure would work with the CI hood/seal so maybe thats the answer...there was a previous thread that spoke of HP gains using rect port mainfolds with oval port heads so maybe this further supports the conclusion not to go to a performer rpm but rather the LS6 manifold
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Rich
Cocoa Beach, Fla
Team Chevelle #380
[email protected]
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[This message has been edited by 70 SS 454 (edited 12-03-99).]
[This message has been edited by 70 SS 454 (edited 12-03-99).]