Found a shop that sounds competent enough and will advance my timing more than stock so got an appt tomarrow to get timing and valves done. From what I am readung 16.5* is optimum??? Mods currently are 100 plate at stock possition (stock clutch doesn't like any more), BHAF, straight 5" exhaust, Star wheel full forward, stock turbo with home made valve running around 35-36 psi currently. I plan on installing a 3k GSK here soon too. I want this truck to be reliable more than anything. I tow my 4X rig so about 5-8000 lbs loads and snowmobiles over mountain passes. Does 16.5 sound right for what I do?

 

Sounds like that would do you well, once you bump the timing and put in a GSK you will have a new truck. Get a clutch from Dan at ValAir, they make awesome clutches and you really can't beat the price...

 

i think youll be plenty happy with 16.5* You should see a noticable decrease in EGTs as well. I 2nd the motion for the valair clutch, if youre not planning on making crazy HP. 2 of my friends bought one for each of their trucks and had great luck with them.