Rear End woes....Help Please
#1
Rear End woes....Help Please
I have a 55 Ford F100. What kind of Diff do you run in yours???? I put a 4.11 Posi Track from MAE RACING in mine. When I am going down the Hwy around 60(not sure because trans cable is not right) it seems I am doing around 6.5K RPM with a 460/C6 combo. No overdrive on trans. I know that is way too high RPMs and it also makes my temp gauge go way up. I still have the old center I think it is 3.0 Gears..39x13 gears...If the 4.11 is way to high will the 3.0 gears interchange with the MAE posi? Thanks for your help
Patrick
Patrick
Last edited by superman64011; 03-31-2005 at 02:10 AM.
#2
Join Date: Apr 2002
Location: Littleton, New Hampshire
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Patrick,
A 4:11 gear is too high for highway cruising with a 460 unless you use it with an AOD. Large displacment engines do not like high RPM and are better performers in the low and mid range RPM band. The 460 would be much more comfortable with a 3:00 to 3:50 gear. I can't answer your question about the interchange.
Vern
A 4:11 gear is too high for highway cruising with a 460 unless you use it with an AOD. Large displacment engines do not like high RPM and are better performers in the low and mid range RPM band. The 460 would be much more comfortable with a 3:00 to 3:50 gear. I can't answer your question about the interchange.
Vern
#3
6,500 RPM is way too high. 4:11 gears should be running about half that at highway speed. Still on the high side if you do a lot of highway driving but that isn't why you got 4:11s in the first place, is it. First thing is get someone with a working speedo to act as a pace car so you have a constant speed. Also, and I know this may sound dumb, but are you sure the tach is hooked up correctly. Most have switches in the back that indicate 4-6-8cly. If it's on the wrong clyinder position, it could explain the high RPM reading. I've had friends play worse jokes on me. Good luck.
#4
#5
Super -
I run a 351C, not a 460, but I have a 3:50 (posi) rear end. I have P295/50R15 (27" tall) rear tires and do around 3200 rpm at 70 mph.
This is a cool little website that lets you calculate what your rpm should be given tire size, tranny ratios and rear end ratio. Check it out.
http://www.car-videos.com/tools/speedrpm.asp
I run a 351C, not a 460, but I have a 3:50 (posi) rear end. I have P295/50R15 (27" tall) rear tires and do around 3200 rpm at 70 mph.
This is a cool little website that lets you calculate what your rpm should be given tire size, tranny ratios and rear end ratio. Check it out.
http://www.car-videos.com/tools/speedrpm.asp
#6
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