350. TH400. 241. 4.56 gears. 37" MTR's. Anyone know?
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
How many RPM's at 70 mph?
- Thread starter cbbr
- Start date
More like 3100.
CDA 455
3/4 ton status
And then you have to add a little more because the trans will be slipping.
NEK5
3/4 ton status
According to RatFactor (best one I`ve found yet) you`ll be at 2899.
link:
http://ratfactor.com/vehicle/gearratio.php?go=y&trans=th400&tcase=np208&diff=4.56&tire=37&crawler=
link:
http://ratfactor.com/vehicle/gearratio.php?go=y&trans=th400&tcase=np208&diff=4.56&tire=37&crawler=
CDA 455
3/4 ton status
Thanks guys. I was thinking around 3000, but kept getting diferent answers, now I know why.
So next question - will running the 350 at 3000 bother it? I have no idea where it should be running in the RPM band on the highway.
So next question - will running the 350 at 3000 bother it? I have no idea where it should be running in the RPM band on the highway.
NEK5
3/4 ton status
Uhh, I`ve heard the desired range for a SBC with an OD trans going highway speeds is 1800-2800 RPM, may be wrong though...
supersize75k5
OrganDonorRacing.com
3000 rpm is working the motor a bit.
have you been in the truck or trying to look at it on paper first?
alot of my past trucks I liked to stay between 1800 to 2500 rpms, any higher and I always felt like the gas was being gulped or the motor was getting a slight work out.
have you been in the truck or trying to look at it on paper first?
alot of my past trucks I liked to stay between 1800 to 2500 rpms, any higher and I always felt like the gas was being gulped or the motor was getting a slight work out.
Last edited:
Muddytazz
1 ton status
Ok, not to hijack a post but its along the same lines.
37's, 350/700/208
I want to have power to pull a trailer over a mountain.
37's, 350/700/208
I want to have power to pull a trailer over a mountain.
Punch those numbers into one of the gear calculators we just listed. If you dont know ratios in the transmissions, 4lo.com has them listed. You didnt give axle ratios either but you can plug in whatever you want.
Muddytazz
1 ton status
The 3/4tons currently have 4.10's in them. I'm thinking of either running 4.88s or 5.13s
Muddytazz
1 ton status
According to the ratfactor site, 2283rpms at 70mph with 37's.
yeah i was off by alot the 4lo.com calculator said 2200 but then you also gotta remember torque converter lock up.. so if you feel frisky go 5.13 lol
Muddytazz
1 ton status
Hell, my old burb had a TH350, 4.10 gears and 33's and ran around 2800 at 70
I'm leaning towards the towing power.
I'm leaning towards the towing power.
Mine sounds like its working a bit hard, maybe bigger tires are in order...
