I've got a BB Malibu and run a RPM Air Gap. I'm wanting to try a 4-hole 1" spacer but was wondering how the cut down divider affects them.
All our local tracks are 1/8th mile and I have a good base line of what it runs and was thinking a spacer may help.
Thanks.....and good to be here.
Dan  

Are you looking for more top end? If so, open is the way to go.4 hole is an attempt to stimulate torque.Either open or 4 hole will work fine with a lower divider  

Open spacers are almost always the ways to go with a dual plane intake. The 4-hole spacers elongate the carb barrels, increase air speed into the manifold, and it will actually make it more difficult to draw charge at high speeds (hurts top end power).

A lot of aftermarket manifolds have a plenum volume that is on the small side for a "large" displacement engine of the same family. Understand that the induction volume for a big block Chevy manifold will have to supply a 396 at low speeds so the optimal volume for a 454/468 would have to be achieved using spacers.  

Thanks guys for the replies.

I've actually got an open and a 4-hole to try but was thinking that since it's just an 1/8th mile that the torque on the bottom with the 4 hole would help more than the open....if either of them help at all.

I was mostly just curious if the cut down area of the divider would hamper or hurt the airflow using any kind of spacer. I remember cutting out material before the companies did, but that's been years ago.

Thanks again,
Dan