Ok guys. Engines are out of my boat now and I am doing some mods. I currently have two different manifold sets. OVAL port air gaps and rectangle port victor jrs. I understand from reading around I could technically run the air gaps on my rectangle port heads. Which would be better for my specific application.
Specs:
489 @ 8.7 compression
Enginequest 320 heads stock with intakes backcut 30
Quickfuel 750 with k n arrestors
741 crane cam
1.7 crane gold rockers
Gil dry to tip exhaust
Peetronix billet marine distributors

imo the victor jr would be the better choice,i also believe the 750 is to small.

I keep hearing its too small but I am building it up little by little as money allows. Next will be some carbs. So you dont think the single planes and lower compression will make it too doggy off the bottom end?

stay with matched to head victor jrs, they dont give up that much mid range wise

Your cubic inch as far as I'm concerned could go either way but my choice would be have somebody port match your vic jrs and you'll be happier on top end. The air gaps from what I understand are very inefficient but would give you a little more punch mid range but lose on top. Yes you can run oval intakes on rec port heads but the velocity starts to get lazy in the runner unless you opened them up to match heads also. Most all builds 468 And up use single plane for a reason. Dual planes work nice and torky on right app but with your build I think your engine will be happier. One of them members here on oso did some testing and tuning on an air gap and the numbers were all over the place. Using your Vic jr make sure you spend some time matching up and getting back into the intake manifold port at least an inch and sometimes more just depends but think of it as a funnel. Sometines you can get away without port matching but there is up to 40 hp plus or minus there to be had or potentially lost if you

I may be interested in an Oval port airgap if it comes down to it. I spend 85% of my time below 4K rpm.

On most aftmkt rect heads, intakes with the bolt hole in between the middle intake runners exposes itself to the heads intake runners...big vacuum leaks...you need to tap these holes on the intake and plug them.

That said, I don't know if the oval gap rpm intake has enough material on the sealing flange side to cover the rect ports on the heads.

With that said...If given the two choices I'd go with the Victor Jr's.