[HO455]

Update time. The bracket I used for the detent cable (kickdown cable) ended up being wrong. It would not let me get more than about 30% opening of the secondaries. In addition it would want to down shift too often. I spent several hours looking through the interweb I came up with no real information other than folks saying "I used this $Xxxx dollar aftermarket piece". I didn't see a need to go that route as the GM bracket had to be out there. Just trying to keep that "Great GM feeling".
I started a thread looking for more information on the truck side and got a lead from member AussieinNC. So off to the wrecking yard I went an gathered up 4 different brackets and came home. Several hours later I had found a solution that gave me proper shift down and 100% throttle opening.

Here is the basic bracket differences from the thread and some photos:

After spending half a day at the u-pull it yard I came home with 4 different brackets. They came off of 83 GMC Caballero (2), a 1995 Van (3), a 79 C10 (4), and a 77 Oldsmobile Cutlass (5).
The photo also shows the one I had installed on the WMB (1) that was incorrect. The brackets are sort of arranged to show the the difference in the detent cable locations. (Blue lines.) The red arrow indicates the bolt hole that the last bolt on the intake manifold would go through. The #5 bracket only bolts to the carburetor back bolts so I was less accurate in placing it.
I initially went with the #5 bracket as I liked the all in one bracket and it was within the range of adjustment for the detent cable. However after I got it cleaned up, painted, and installed I realized that I could only get 90% opening of the secondaries. The angle to the throttle shaft arm was wrong. 90% was much better than before but I real want 100%. So I ended up pulling it off and using the #2 bracket and my original (Original in that it was on the truck when I bought it.) bracket. Now I have full throttle opening and the transmission shifts down nicely.
The 2nd photo doesn't have the throttle cable bracket installed and the 3rd photo shows the original detent cable bracket. Poor photos are really showing what I would like to show. Hopefully folks get the idea. If not let me know and I can get some clearer pictures.

Here is the complete thread if anyone is interested.
http://67-72chevytrucks.com/vboard/s...d.php?t=630289



The next issue is the converter lockup doesn't work internally as I had been led to believe. I was under the belief that the lockup pressure was tied to vehicle speed in 3rd gear i.e. if the vehicle was going 40 mph there would be 40 psi, 50 mph would be 50 psi. The lockup wouldn't lockup until the minimum pressure was met. I was lead to believe that GM had set the minimum pressures to 50 psi so the lock up would not work below 50 psi.
Unfortunately for me the converter locks up as soon as the truck gets into 3rd gear. Which can be as low as 30 mph. So at 35 mph any part throttle acceleration results in pretty serious detonation. By disconnecting the power to the lockup circuit the problem disappears. At this point I will have to go with manual operation of the lock up until I can get quite a bit more sophisticated with my control circuit.