I bought a used 16' smoker craft welded sled with a 90hp jet pump with a 8 hp kicker that weighs about 1700 lbs., and had no trouble towing it 300 miles but going up a steep hill I could only go 50 miles and hour. My Toyota Tacoma is a 2008 4 cyl with 4 speed automatic trans. I checked with several people and mechanics the answer for me was the differential to get higher rpms. ECGS sold me a 4.3 dif from the original 3.58 now I have the rpms to tow. Nothing else helps except buying a rig with a v8 engine.
ecgs; east coast gear supply 919-672-2705