We have a 97 5 speed that had 5x18 dual feeds, 21* timing and a silver bullet 66. We towed **** all over with that thing. Unhook from the trailer and sled pull then hook back up to the trailer and go home if it didn't break. I hauled all sorts of crap like I motorhome back from ft Wayne IN, tractors, hay and my Pullin truck everywhere. With the 3.55 gears it would have trouble finding a sweet spot when hauling heavy and trying to pass or climb big long grades. We put 4.10 gears in and it made a world of diff on accelerating and egts. The downside was its unhooked performance became kinda lackluster. It didn't seem to pull as hard and just seemed overall slower. Plus when sled pulling now you had to run low 4th and with a 650hp street truck a 11.11 gear was a bit much. With 3.55 it would run easy 1200-1250 egt while cruising down the interstate. With the 4.10 it dropped to about 1050 egt
In summary, i wouldn't do it too much anymore. Crappy mileage, smoke and now that I look back, a freaking chore to drive. Lol but it can be done
