The kickdown linkage should have about 1-2" of movement, if I remember right, for a TH350, which I will assume is your transmission. Here's how you adjust the kickdown linkage:
1) First, determine how far the throttle lever goes with nothing connected.
2) Then, hold the throttle lever at WOT, and pull on the transmission kickdown linkage as hard as you can. The idea is that kickdown cable is pulled out as far as it goes when the throttle is at full position.
3) Adjust the kickdown linkage to be out all the way when the throttle is at WOT. Depnding on your setup, you may have to turn a plastic part, or adjust a bracket. Can't tell without seeing a picture.
4) Connect the th. lever / trans kickdown cable at this point (WOT / kickdown full out)
5) When you let go of the throttle now, you'' probably get slack on the trans kickdown cable, and the cable will not tighten up until the throttle is something like halfway to WOT. This is normal.
The tension on the throttle is normal after you open the primaries more than 65%. That carb has the secondaries open based on throttle lever position, and you're fighting a spring to open them. Also, if the kickdown linkage is hooked up prperly, you're also fighting the kickdown linkage. All normal.
Don't forget to connect a good throttle return spring!
"...it costs what now?" Lev
Team Chevelle Member #590
70 Malibu, 396 "LSE" powered