you must have had tuning issues. there's plenty of guys on here that tow with a single 366 I run a singe 467 I don't tow but its not very laggy even being stock fuel
I have a brand new single kit from Midwest. Everything is there for install. Never used. Cast Borg Warner 366 t4. 66/73/.91 $1,800 shipped. call or text 631-603-2854