need help with rear for tow rig.. off topic but you guys will know the answer

R

rayjon

Venimus, Vidimus, Deus vi
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May 30, 2008
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I have a 3500hd chevy 1995 with a 37 spline dana 80 in it, Did a cummins swap and working on a fuller 10 speed now, the problem I have is the 3.54 gear set I swapped into the dana 80 isn't working on the highway. I need 3.08 and something a little stronger if possible..

Here is my delema I have a small 10 lug pattern 7.5 not the metric pattern ford uses so a s110 is out.

Does anyone know of a rear that is bigger than a dana 80 comes in 3.08 and uses the old chevy mini 10 bolt pattern with Juice brakes..

I can also convert the brakes if ends are similar..

Thanks for the help
 
What size tires? Seems like that might be easier to change than rear ends.
 
Have the 10sp made in a OD I had my RT6610 made in a RTO6610
I had 3.54 also.

Dale
 
the tires are 225/70/19.5 brand new all the way arround, cant really step up on the tire size due to the custom hauler bed i built and level of the truck now.. Its a crew cab built by monroe truck for a local city 18k gvw that I picked up second hand with 30k miles on the clock and a dead 6,5

the 10 speed will be an rto610 have a rt610 and am changing the gears to make it an rto

what I am trying to get to is under 2000 rpm running empty on the highway, Nevada is big and I have found with my other trucks if I keep the cummins under 2k I can get 20+ on the highway. that is the goal.. and with the 10 speed I will have all the gearing I will need, not to worried about breaking the dana 80 with only 350hp but would like to drop the rpm some more at 70mph.. I have the turbo and low end to pull the gear.. just trying to figure out how to get there with this combo.

thanks for the quick response..
 
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How tall are the 19.5.I was running 2300 at 70mph with 29" 235/70/16 3.54 .80od.I got 25 empty.You will have the same OD as the RTO6610 once you switch over.With the allison 6sp I will be doing 1728rpm at 70mph when I get the truck back togetherOD in the allison is 5th.71:1 and 6th .62:1.My speedo was on the money with a GPS.So if your tires are taller than mine your RPM will be alittle less.

Dale
 
the 19.5's are about 32" with the nv4500 I was at about 2100 at 70mph, the differnce isn't much but it should go up just a tad as the nv4500 is .75 and the rto is .80 in overdrive.. I will give it a while and run the 3.54 like you sugest and see what it does..

did find that the dana 135sl has ratios down to 2.61 and all I would have to do is swap the hubs off my 37 spline dana 80..
 
I believe you can get a 3:31 gear for the 80. May not be enough for you though.
 
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