[JohnIL]

One step forward, two steps back.

Grounded63's suggestions led me to go take another look at the throttle linkage and bracketry. I've looked at it at least 50 times and I never realized the geometry was wrong. It turns out that the previous owner didn't bother to install a TV cable correction bracket on the Edelbrock Performer carburetor. That will obviously throw off the TV cable adjustment. I managed to find that part (Edelbrock 8026) at a local O'Reilly.

After installing the bracket, it's now obvious that the previous owner didn't use the right throttle cable/TV cable bracket on the back of the carburetor. Now, the TV cable is offset out of alignment by about 1". There's no way that's going to work right. So, I ordered a different bracket, specifically for the Edelbrock Performer/AVS carburetor. It's from Jegs (part# 157313). It won't arrive until the end of the week. So, now we wait...

I don't know for sure if fixing the geometry will fix the shift points, but it makes logical sense. The way it was, the TV mounting point on the throttle bracket was about 3/4" too far forward. That would put way too much tension on the TV cable as the throttle travels forward. Logically, that would raise the line pressure significantly and cause the transmission to shift very late.

Fingers crossed that this fixes the problem. I'll report back when the new throttle bracket arrives. Thanks again for your advice.

John