SOLVED! 318 2500-3000 rpm idling issue. Don't think its a regular vacuum leak. Swapped 2 intakes, 2 carbs ,and 6 different gaskets still no luck.

Alright everyone, apologies for he delay, but I've been hard at work and got a second in person opinion from someone more experienced with built motors and we have discovered the problem, I'm just a dingbat.

The engine, was running fine. Very rich but I'll explain.

This car has an obnoxious short exhaust on it, side exit and straight through flow fx mufflers. So it's loud and this is part of what was throwing me off. I was misreading my vacuum gauge and it was pulling 10in of vacuum, 12* initial, my tachometer read 1600, but the thing was set to 4 cylinder mode meaning it was actually running at 800rpm.

First issue.

Second issue, my power valve was a 6.5 in and was hanging open hence the rich plugs and pig rich exhaust.

So I reached out to a experienced engine builder machine guy who did my Pontiac block, guys 91 years old and sharp as a tack and agreed I needed a 3.5in power valve and it cleaned the idle right up. The carb probably still needs tweaking but I simply lacked the in person experience with engines that aren't just stock 350s and 389s that I was thrown off by the sound and vacuum and idle stability.

Now it runs pretty good, got a little backfiring but I probably need to get the engine under load and drive it. Maybe open the secondary throttle blades a bit and back off the transfer slot on the primary throttle set screw.

Just a lack of experience as this is the first engine I've built that's run and the first performance motor I've ever worked on.

Thank you all even if it was all my fault!

Any further tuning advice would be appreciated with my setup!