I have a 70 318 that many years ago I put a set of 360 heads on and bolted on a stock 360 4 bbl spreadbore manifold. Now I know that this configuration has a huge problem primarily because the combustion chambers are huge and will lower the compression ratio to pretty near 7:1. Now while it runs ok and will not "ping" even on the trashy gas I know I can do better. So Im thinking about getting a set of "302" swirl port heads and going with an aftermarket 4bbl manifold. My question is what will fit and not cause any fuel turbulence or reversion problems between the new intake and the '302" head intake port?

Just run the intake you have you will not notice anything. I ran that exact combo for years on my 87 Diplomat. All this runner mismatch hype is nothing but turd polishing on a relatively stock 318. You'd notice more putting in a 340 cam and that would be a better place to spend your money.

Mild cam, headers and MP ignition installed years ago.
Im looking to confirm if any aftermarket manifolds match the 302 port.

I never measured the port int he 302 heads so I dunno, it's real narrow around the pushrod bulge

I am looking at an Edelbrock Performer 318/360 to see if it will work PROPERLY on the "302" heads. I know it will bolt on but will it work properly?

The best manifold for a 318 is one w 318 sized ports....The only one ever made was by Edelbrock in the old days....model D4B it has GREAT throttle response and is the BEST manifold I've used on a 318 bar none.

The Edelbrock Performer has 318 port size and works great. Plus you can find them everywhere.

I have 302 castings and the Edelbrock performer intake on the 318 in my SE Charger. I didn't have any problems, but I did match the ports to the gasket.

The Weiand Stealth (or Action Plus for spreadbore carbs) is nearly an identical match to the LD4B. Ports on the one I have had a LOT of variation in size but most were closer to the 318 port opening than the larger 340/360.

You are wasting your time.

The pushrod pinch is substantially smaller than the port entry so who really cares if the intake and head port dimensions match.

The port mismatch may be an issue when you get into the upper rpm range, say over 4500, and that might only show up on the drag strip where tenths of a second matter. How often do you think your motor will be in that rpm range?

If its a concern, you could match the top and the inside of the ports to the gaskets, then any intake will work.

I ran a set of 318 heads with a 340 intake in a motor with a big cam back in the day. The small ports make more of a difference then the mismatched ports by the increase in throttle response. The motor would run out of air about 5,000 rpm because of the small ports, so I just shifted a little quicker. I gave a lot of fast rides to a lot of people, no one ever commented on the mismatched intake ports.
I think you are over thinking this. Gene

The old Street master had 318 ports also.Have one I bought used and never did use as my son sold his truck.Not the greatest for performance but IIRC they do run decent and are cheap.Rocky

I have a Holley street dominator with 318 ports. Supposed to be pretty goood on a 318.

i had an old SP2P edelbrock intake laying on the shelf that also had the small 318 intake ports. i gave that intake and an old truck motor to my buddy for his duster. he put on a 500cfm edelbrock carb and a 1" spacer. that thing runs sweet, using a 340 4spd cam.

I think all you need is an Ebay turbo and a blow thru carb. That will eliminate the need to change the cylinder heads and solve your port mismatch dilemma.

Kevin