Ok I want to replace the stock Merc intake on my 86 454 Cyclone 440s. I was thinking about going with Eddelebrock rpm airgap intakes. I have GM rectangle port heads that have not had any work done to them that I know of. Any outher intakes I should think about.

The dual plane air gap would be my choice. I have run dual plane performers and single plane darts back to back and the dual planes worked best. I too run rect ports on 454s.

The rpm air gap is a nice manifold and would work well for that type of engine. PM me, I may be able to help out.

I have on mine edelbrock Victor jr. Runs fine 454-420 now up to 485 but also cam change.