Current Pete has a 400 big cam, 15 speed, 40 inch tires a 3.54 gear.
It sucks. Overdrive is only really good over 70, and it doesn't have much ass behind it.
We are keeping the motor, but changing the rear and the tires. Tires will be 42s.
New rear will have an air locker and a new, non oil soaked suspension, but that suspension will depend on a bunch of things.
A couple things to consider:
Big cam makes 1,200 ft/lbs at 1350 and torque curve crosses the hp curve at 1550 rpm, but it really prefers 1700-2100 rpm. Redline is 2400, but under load, probably 2250-2300. It's a big industrial motor, you can run it hard all day with no problems.
Realistic top speed is 80. I did push it to 85-90 for three hours across Kansas once shooting the gap between thunder storms, but it's a rare thing.
Splits on the super 10 are all 35%, so it not really worried about the rest of the gears as long as I get the top 2 right.
Current 15 has a .75 over like the new super 10.
"Factory"
Direct is 57 mph at 1700 and 71 mph at 2100
Feels best around 65, or 1900 rpm
Overdrive is 76 mph at 1700 rpm and 94 at 2100
Feels best around 78, or 1740. Really that's about as hard as I like to push it speed wise for a long amount of time. It still feels sluggish at those rpm.
3.73s with bug rubber puts us at the same numbers as 3.54s on small rubber.
3.90s on new tires will put us at
Direct: 54-67 and 65 mph at 2000 rpm
Overdrive: 67-90 and 75 mph will be 1750 rpm
I think that's about as low as I want to go. If you get into 4.10s it shifts it down even more
Direct: 52-64 and 65 will be 2130 rpms
Overdrive: 64-85 and 75 mph will be 1850 rpms
If I were heavy hauling, I would go for 4.10s but we usually gross 45-55k which is nothing for this chassis.
Old school truckers will tell you to gear it to run 100, but the 3.54s will run 99 and it's just too tall. 3.90s will run a little over 90 flat out, which is more than fine.
My only worry with 3.90s is the 65 mph range, which is run quite frequently. It will be either close to max rpm or in the bucket at 1520 rpms. That speed has to come up sometime, and I guess 65 is a good enough speed for it to happen.
I would love a .89 or .85 overdrive, but we already have the super10 in the shop and I think it's better over all.
It sucks. Overdrive is only really good over 70, and it doesn't have much ass behind it.
We are keeping the motor, but changing the rear and the tires. Tires will be 42s.
New rear will have an air locker and a new, non oil soaked suspension, but that suspension will depend on a bunch of things.
A couple things to consider:
Big cam makes 1,200 ft/lbs at 1350 and torque curve crosses the hp curve at 1550 rpm, but it really prefers 1700-2100 rpm. Redline is 2400, but under load, probably 2250-2300. It's a big industrial motor, you can run it hard all day with no problems.
Realistic top speed is 80. I did push it to 85-90 for three hours across Kansas once shooting the gap between thunder storms, but it's a rare thing.
Splits on the super 10 are all 35%, so it not really worried about the rest of the gears as long as I get the top 2 right.
Current 15 has a .75 over like the new super 10.
"Factory"
Direct is 57 mph at 1700 and 71 mph at 2100
Feels best around 65, or 1900 rpm
Overdrive is 76 mph at 1700 rpm and 94 at 2100
Feels best around 78, or 1740. Really that's about as hard as I like to push it speed wise for a long amount of time. It still feels sluggish at those rpm.
3.73s with bug rubber puts us at the same numbers as 3.54s on small rubber.
3.90s on new tires will put us at
Direct: 54-67 and 65 mph at 2000 rpm
Overdrive: 67-90 and 75 mph will be 1750 rpm
I think that's about as low as I want to go. If you get into 4.10s it shifts it down even more
Direct: 52-64 and 65 will be 2130 rpms
Overdrive: 64-85 and 75 mph will be 1850 rpms
If I were heavy hauling, I would go for 4.10s but we usually gross 45-55k which is nothing for this chassis.
Old school truckers will tell you to gear it to run 100, but the 3.54s will run 99 and it's just too tall. 3.90s will run a little over 90 flat out, which is more than fine.
My only worry with 3.90s is the 65 mph range, which is run quite frequently. It will be either close to max rpm or in the bucket at 1520 rpms. That speed has to come up sometime, and I guess 65 is a good enough speed for it to happen.
I would love a .89 or .85 overdrive, but we already have the super10 in the shop and I think it's better over all.