I have a 68 C4 transmission on my SBF. I'm running a B&M quick shifter. Not sure where to look to fix my problem which is this. The transmission shifts fine when normal driving. If I put it in 1st gear and WOT, then click it to 2nd gear, it won't shift instantly into 2nd. If I back off the gas pedal, then it will shift hard into 2nd. If I stay on WOT, 3rd gear works fine. Is there an adjustment for this issue from 1st to 2nd with WOT, or what could be the issue?