Just got finished rebuilding the transmission and decided to buy a Superior Transmission shift kit for my van. There were two sets of instructions in the kit. One for manual and one for standard. I did not want the manual so stuck with the standard plans. The standard plans also have a "heavy duty" option which uses more parts and drills out some holes in the spacer plate. Anyway, it is just a van and I do no heavy hauling or pulling of a trailer. Would there be any reason to use the "heavy duty" option? Also, I have noticed that some members do drill out some of the holes in the spacer plate to make the 2-3 shift better. I did not drill any holes and just wonder if maybe I should have?