I think zippy's long post hit it on the head. Due to your heads and displacement you could run a 220 or even 224 duration cam and still be able to tow and get the gains you want in the rpm range you need. I'd also go with PAC singles or orange or yellow Z06 springs, and get I'd go 2400 stall with a 218/220 565/565 112 lsa or a 2600 stall with a 220/224 578/578 112 lsa. Get a big tranny cooler and mount it in a good location where it will gets lots of air if you will be towing a lot. GL!!!