Would putting an open plenum 1" spacer on a dual plane intake hurt performance at all. I was thinking of just grinding the middle section of the intake (the wall seperating the two sides), to a sharp edge.

 

I dont think it would hurt, it basicly does what you say you wanted to do but adds to the manifold volume. Seeing how higher HP manifolds have this crossflow section, lol including stock intakes.

 

You've essentially got a built engine with a small carb on it, I think any increase in plenum volume will help you. I'd try and get as much as possible considering that you likely have all kinds of clearance between the TBI and hood in your P/Up.

Couldn't help but notice your best G-tech pro time was at zero Celcius - only in Alberta!

 

Yes alberta can be cold!!

I know getting more plenum volume will help me, I don't think I can squeze a 2" spacer under my hood, I'll go out tommorow and try to measure the clearance.

 

Make the plenum divider a rounded edge, not a sharp one.