If you are going to stick with stock injectors, my vote goes to a 62/68/12 or 62/68/14.
Run those twins, those injectors, and a Hamilton cam and forget about it. That'll be a great towing setup.
I've had good luck with Zach's 181/210 and a 62/68/12.
Glen what truck where you running this set up on 2nd or 3rd gen and what injectors are you running?