I have two throttle cables that look to be original equipment: one cable has a housing length of 11-1/2" (measured from firewall to carb), the other cable has a housing length of 13". Is the shorter one for a Q-jet and the longer for a 2BBL? I've installed the longer cable with a FiTech EFI throttle body and the cable fits tightly, but has to arch upward before getting to the firewall. Should I be using the shorter cable?

 

Hard to tell from the pic, but that curve doesn't look too bad. If you disconnect the cable from the throttle pedal and and throttle body linkage, does it move smoothly with your hand?

I am using a universal throttle cable from the parts store that I cut to fit and it's also adjustable. I think it's Spectre brand?

 

I re-checked the throttle balance, which was fine, but found the return cable was a bit slack, in fact I had to take up about 5mm of free play in it. Having done that, a quick test ride showed it had completely cured the problem and totally eliminated any previous rough running. I couldn't believe how such a small adjustment could make such a difference ! I've concluded that, although I had taken out all the slack in the pull cable, I had left too much in the return cable, which was allowing the throttle body valve to "float" slightly and upset the mixture control when it's only open such a small amount. Kodi Lucky Patcher nox