The Venom is designed to fit BBF engines with CJ style heads. Users with SR71 heads should use China Rail Spacers available from Jon Kaase Racing.
Dyno proven 30+ HP gain over a highly modified TFS "Mafia" intake on a 580" SR71 Head engine. This intake accelerated the dyno harder and faster than the Mafia also, which translate to faster ET and MPH on the drag strip, and more wheel speed on the truck pull track.
We continue to do additional dyno testing on a variety of different CJ head engines from 470 - 600+ cubic inch. ALL of the engines dyno'd to date with the Venom (AND SUPPORTING PARTS SUCH AS APPROPRIATELY SIZED CAMSHAFT AND CARBURETOR) have increased both HP and Torque.
This manifold is recommended for larger cubic inch SCJ headed engines.
SMALL cubic inch engines MAY require a small amount of epoxy in the bottom of the intake runner / head port to achieve maximum performance. This should be discussed with your engine builder to achieve the best gains.