Intake Manifold
All Star
Joined: Feb 2008
Posts: 941
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From: Odessa Tx.
You can fab up an adapter out of 1/2 plate steel or aluminum for the TBI. Built one for my 360s stock carbed manifold. If it's a dual plane you may have to cut down the center divider in the plenum to clear the throttle blades. Did this on my '86 4x4,where HP [RPM]isn't much of an issue,but steep angles without flooding is.
Not sure how much of a perf. gain you'll get with an aftermarket dual plane over the factory TBI one. Aftermarket carbed dual planes are basically designed to optimize the vacuum signal on a carb's boosters.
Since a TBI doesn't rely on vacuum to supply fuel,and if airlow/port velocity is your goal, on a stock motor I'd try an early factory 318 cast iron single plane [some 60s,rare,hard to find]and a 360 throttle body. The factory single plane's ports are sized for the 318,and it has the two bbl flange. Clean up the ports and gasket match 'em to the heads.
Most aftermarket single plane's ports are too big for a 318. Port velocity will suffer until you reach high RPMs,a moot point on a stock motor. Just remember the 318s small ports/valves in the heads and tiny cam are a cork to any real gains.
A swap to a Hughes cam and porting the heads would give you some gains. Overall just the intake is not much worth the hassle in my book.
Not sure how much of a perf. gain you'll get with an aftermarket dual plane over the factory TBI one. Aftermarket carbed dual planes are basically designed to optimize the vacuum signal on a carb's boosters.
Since a TBI doesn't rely on vacuum to supply fuel,and if airlow/port velocity is your goal, on a stock motor I'd try an early factory 318 cast iron single plane [some 60s,rare,hard to find]and a 360 throttle body. The factory single plane's ports are sized for the 318,and it has the two bbl flange. Clean up the ports and gasket match 'em to the heads.
Most aftermarket single plane's ports are too big for a 318. Port velocity will suffer until you reach high RPMs,a moot point on a stock motor. Just remember the 318s small ports/valves in the heads and tiny cam are a cork to any real gains.
A swap to a Hughes cam and porting the heads would give you some gains. Overall just the intake is not much worth the hassle in my book.