Guilty..... It's a '98 Lo Pro F-800 with a 190hp P7100 pumped 12 valve and an Allison 545 slush box w/ 3.58 gears and 33" tall 19.5" tires....... 2 trailers on the truck usually weigh 8k - 12k GCW is 20k - 24k loaded.
Bumping the governor at 2600 puts me around 67 mph. Problem is these engines are way out of their power band the way Ford geared them.
I'm fixing to solve that soon
New engine going in next month with a #6 fuel plate and bumping the timing to 13* which should put me around the same power I have in my Dodge dually that pulls better with heavier loads. Also looking for a Fuller RTOO9513 13 speed double overdrive w/ 1-3/4" input shaft and an SAE2 bellhousing to back it up
10th gear 1:1 - 60 mph @ 2187 rpm - Hill pulling gear
11th gear .84:1 - 60 mph @ 1837 rpm - loaded cruising for economy
12th gear .73:1 - 70 mph @ 1862 rpm - deadheading back for another load
13th gear .62:1 - 80 mph @ 1807 rpm - deadheading through desert
13th @ 2600 rpm ------ 115 mph
SEE YA!!!
Ya a single overdrive will get the job done too but 3 OD gears is more fun.
Gear fast and run slow for economy. I think these engines would do much better if they were geared properly to keep them in their power band.