[JJKJ]

The new engine is running great but I have a slight issue which may be a common problem or not but I haven't run into it before. After I drive the car and it warms up, if driven docile, the car comes back down to idle as normal. However, if I get on the car during the drive (going WOT or close), the car sometimes does not return to normal idle. Instead it idles about 200-300rpm higher than normal. It is not on the high idle cam and the primary throttle linkage seems to be down tight on the idle set screw. If I remove the vacuum advance, there is no change, but I'm wondering if my mechanical advance may be sticking? Tapping the throttle has no effect bringing the idle back to normal. Here's a few other details:

The distributer is a new HEI unit

I rebuilt the carb and installed bushings on the primary throttle shaft pre Cliff's book so the primary throttle shaft is operating smoothly and seems to be going closed completely

I have my TH350 governor set for pretty conservative part throttle shifts as I was breaking in the engine so part throttle easy shifts rare gets the engine above 2500. If I keep the car driven in this manner, I don't recall having the high idle problem.

Thanks,