Yep, car is at the point that it stalls at every stop, feels like a misfire (timing?) & surging idle. This car is driving me crazy! lol I gotta get the car back to the garage tomorrow, check for codes, no light on so? IDK. I'm probably going to pull it apart tomorrow, check for slipped intake gasket? I can't find any vacuum leaks other then the TPS center and the TB butterfly at bottom of TB? I'll rip it apart one more time, if this don't fix it, either stock intake or carb setup. This is the 4th week working on this here and there so, one more try! Wish me luck.None of that should affect how the car runs significantly.
I still suspect vac leak due to manifold gasket.
Dunp codes and perform the cylinder balance test procedure. See if you actually have a misfire or dead cylinder.
The CEL light being on doesn't necessarily mean there aren't some codes present that might give us a clue as to what is going on. The cylinder balance test procedure is also a good thing to try to see if you get a passing code for all cylinders. I think only 11-13 of the codes actually turn the light on, but there are something like 50 or so potential codes. It's not like OBD2 where every little thing turns the light on.
A slipped intake gasket won't necessarily show as an external vac leak. It's possible for the gasket to slip in such a way that the leak path is into the lifter valley where the hydraulic lifters are. That wouldn't show during a smoke test.
Great advice. Simplify a complex system to the base components that should work together, i.e. as close to stock / OEM as you can get.Change one thing at a time. Before you put on the upper & lower manifold, you said it ran. I would restore everything the way you had it, except the manifold. Then, start chasing your issue. You're running the risk of creating a multi-variable problem and confounding your diagnosis.