It is possible the quadrant and or cable is your problem. I certainly would recommend installing an aftermarket cable and quadrant, especially if you have a heavier clutch like a centerforce. Cable and quadrant is not very expensive and a good mod even if your stock one is not the problem. So nothing lost.
I have a Tremec 3550 with a Zoom cable and quadrant with a centerforce clutch. I have to adjust mine from underneath the car but it is adjustable. Now there are some nice pieces out there that are adjustable at the firewall.
My Tremec and clutch has worked very well for me. By far superior to the T-5, can handle speed shifting and slicks. Yet friendly on the street.
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fordgasm
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