7.3 diesel with 355 gears
Has anyone had 355 gears with a 7.3 diesel was thinking about changing to them from 410's but want to know if it will be geared too low, also what rpm will 65mph, be at 410's at 1900 is about 56mph
Forum Discussion
I had a 99 7.3 2wd srw rc auto with 3.73 gears and pulled some monster loads with a gooseneck and also truck camper and everything in between. Keep in mind the gear spacing between 3 and 4 is pretty large, jumping to larger rear gear makes it larger. I always thought about going to something like 3.27 for mileage but never did. Pulling slide in would get around 14 mpg, unloaded 19-20. This is with tall 85 series tires. Cruising at 1900 rpm would be around 65-67 mph.
Had a 2000 7.3 with 2wd drw cc auto and 4.10, pulling slide in it would be 2 mpg less then the above but can't remember at what mph or rpm.
Don't think you want the 3.55 although not much different then the 3.73, the 3-4 gear jump with an automatic and cruising at 65 mph and 1900 rpm is about right with the 3.73. Wind resistance is squared as the speed increases and a lot of that drag is off the back so if you tow or have something to smooth the air flow off the back helps significantly.
Had a 2000 7.3 with 2wd drw cc auto and 4.10, pulling slide in it would be 2 mpg less then the above but can't remember at what mph or rpm.
Don't think you want the 3.55 although not much different then the 3.73, the 3-4 gear jump with an automatic and cruising at 65 mph and 1900 rpm is about right with the 3.73. Wind resistance is squared as the speed increases and a lot of that drag is off the back so if you tow or have something to smooth the air flow off the back helps significantly.
