Perfect street/strip converter

My stock floor shifter in my 74 was running fine, after i shoehorned the 340 with the 8 qt pan and 727 attached. Ps/ pb car. Never again! Adjusted, as i put it together, manual shifted it a few times, it missed a couple of shifts. I wzz working under the hood with the engine running and twice that car jumped into reverse and ran away from me. Picked up a Hurst Pro Matic I'm going to shove it underneath the factory console
I take it u used the 904 linkage which isn’t right for a 727. Kim