Just an update, towed for about 10 hours across KY yesterday with my setup. Only grossing about 17500 or so, was towing a 9.5-10k fifth wheel. Got to see lots of grades and just about any common towing condition except high altitudes.
Was using Jonathon's tow tune, stock injectors, banks intercooler and the brute 66. Truck peformed great. Towed in 5th gear the whole way at 70 mph which in my truck is about 2350-2400 rpm. The truck pulled awesome, never slowed below 65 on the grades using the cruise control. EGT was 6-700 cruising and never got above 950 on grades. Boost on level ground was 4-5 psi, about 14-15 on the grades at 2400 rpm. If I accelerated on grades up to 2900 rpm id get 20lbs or so boost. No smoke, but i do have stock sticks.
My truck is supposed to have 4.10s from the door code, but my numbers always look like 4.30s so i dont know, ill count teeth next time i pull the diff cover. Also has about 3in lift and BFG285/75r16 ATs on it.
Anyway, i was pleased with it. It makes sense that the 66mm turbos will enjoy rpm, which my truck gives it with my low gearing. So for me the brute66 is working fine. I definitely have less smoke than before, and it boosts just as fast although i do have the 1.0 housing so that comparison isnt exactly apples to apples with the stock turbo.
I plan on upgrading to baby swamps or pis 169/30s in the future so im not sure if that will make things better or worse for the brute66. I dont want much smoke so now im not sure if i should upgrade the injectors or not. This truck feels pretty peppy while towing already due to the gearing I guess. might just leave them stock since i mostly just tow with this truck.