Throttle body efi intake

[Recap]

Just installed a Fitch efi system on my 67 Camaro.  The current intake is a dual plane.  Would an open plenum style be a better choice?

[Steve Wood]

In theory, yes.  But, there are a lot of variables and results seem to vary.

If the dual plane has a fully divided intake partition, then the map sensor may detect the flow from one half the engine only...this can lead to erratic AF and incorrect fueling on one side of the engine.

I have heard that a one inch spacer under the TB unit can make large improvements in consistency of AF and lead to more hp across the board.

There is a lot of discussion on this item across the various boards and manufacturers so you might spend some time and see what other users are saying.

[nocooler]

Try it and see how it is - you can always change the intake later.

[Recap]

Did a bit of searching and reading and there seemed to be a lot of conflicting views.  I like your idea of running a one inch spacer.  May give that a try before I run out and spend time and money on a new intake.  I have this installed on a 327 with a comp 268 solid lifter cam, 23 degree trick flow heads, tremec 5 speed and 323 gears. 

[TexasT]

If a one inch doesn't suit you, and you have the under hood space, a 1.5" or 2" might give it more area to pull from . Way cheaper and less laborious than an intake swap.

[Steve Wood]

Yep...A spacer seems like the logical choice

[motorhead]

Plus, the added benefit of increased plenum volume, and maybe even a more homogenous air/fuel mixture.