I'm back. I have almost 900 miles on the new engine/tranny combo and am trying to get the 1-2 and 2-3 upshifts dialed in. While I was breaking everything in I left the throttle pressure on the high side to keep the engine revving and vary engine rpm, but now that everything is getting broken in, I want to set the upshift a little closer to what I want.
Because I went with a quadrajet, I abandoned the factory throttle/kickdown rod in favor of a lokar cable setup. It took a couple of tries, but I eventually fabricated a throttle bracket for the carburetor that would accomodate both the thottle and kickdown cables.
After fabricating and installing the bracket, and then installing the throttle and kickdown cables, the 1-2 upshift was way too high, right around 42 mph on hard (but not opening the four barrels hard) acceleration. I remembered that for the stock linkage you want to shorten the throttle/kickdown rod for sooner upshifts, but with the lokar setup I figured you needed to do the opposite. (page 42 of munroe "when governor pressure overcomes throttle pressure, the transmission will upshift.") so if I lengthen the lokar cable, this means that throttle pressure will be reduced at a given throttle position and governor pressure will more easily overcome throttle pressure...leading to sooner shifts.
So this has worked out. The more I lengthen the cable (by moving the lokar collar further up the cable), the sooner my upshift. However, the problem is that I am having to move the collar so far up the cable that it would appear the transmission is operating without throttle pressure during most of my around the town driving.
I have attached a picture showing what I mean. The throttle cable is on the top, the kickdown cable on the bottom.
Notice that there is about one inch of travel before the plastic slip sleeve with "lokar" written on it hits the cable collar with the set screw in it. As I give the truck more and more gas, the plastic slip sleeve moves closer and closer to the collar. Once the sleeve hits the collar, and I give the truck more gas, the cable is pulled and the throttle lever is pulled toward the rear of the truck, thereby increasing throttle pressure. (note: when this picture was taken, I manually pulled the cable forward until I encountered spring resistance from the throttle lever. The throttle lever on the tranny appears to have about 1 to 1 1/2 inches of, for lack of a better term, "slop" within which you can move the throttle lever back and forth by pulling on the cable with no spring resistance. I can pull hard on the cable and move the throttle lever further back toward the rear of the truck, but as I let the cable go, the spring in the throttle lever pulls the lever back to the resting position where I took the picture.)
after all of that background, my question is this: is it acceptable to run the tranny with so much gap in the throttle linkage (I.e. Little to no throttle pressure at lower rpms)? I've also read the running a tranny without the throttle rod hooked up can destroy a tranny. Should I move the hole up in the throttle bracket to reduce the arc that the throttle linkage has to travel, which will allow throttle pressure to come on more slowly. Right now, because the hole is so low in the throttle bracket, my throttle pressure comes on very quick.
I hope this makes sense.