So, this morning I stopped by Valentino's to have a look at his Bronco as he has been complaining of a no-go situation with the truck. The situation seems to be that when he is driving, despite pushing the skinny pedal to the floor, there is no down shift and no increase in acceleration on hills. I checked out and adjusted the timing, putting him at/around 10* +/- a few (really hard to read his balancer marks) and adjusted his mixture and idle to sit around 13-14lbs of vacuum at idle (the max I could work out with the mixture screws and timing). We then took the truck out for a drive. Over a mixture of hills and flat roads, the problem seems to be the same. Initial acceleration is okay. Getting the truck up to around 35mph is no problem and upshifts seem to occur at about the right times. On approaching hills or dumping the skinny pedal, there is an initial downshift that lasts for about a split second before the truck again upshifts into the highest gear. If manually shifted, from 3rd down to 2nd, there is little change to the situation. Still bogged down. Still very little acceleration. If downshifted in to first, acceleration is there and all seems normal from an acceleration stand point.

Once we returned to his house, I looked over the entire set up. Vacuum lines are present from the back of the carb base to the vacuum solenoid on the back of the transmission. However, the kick down lever mounted on the carb seems a bit weak/floppy to me. Having Val work the throttle linkage, I noticed the kick down lever movement was more lateral (driver's side to passenger side) than front to rear. Basically, its a very wobbly set up and I think the kick down lever may not be fully engaging on hard acceleration.

I went ahead and told Val to pick up the Edelbrock Ford Auto transmission adapter from Advanced and it should be here in a few hours.

Can anyone think of any other areas we need to be looking at to get this thing shifting/delivering power correctly?

The kickdown will help at speeds above 45 or so. Below that it really doesn't have much affect. That's where the vac modulator lives/works. Modulator is ok if the shifts happen at the right time.

If the trans doesn't slip when dropped down a gear then it's probably an engine power problem. 13" of vac is very low with a stock type cam. A compression test may be a good idea.