What R&P's do I need??

specfour

specfour

New member
Ok, I am starting to get a list of parts together for this coming winter's Scout projects.

I have a 1969 Scout 800. It has a 345, a 4 speed, Dana 20 t-case. It has front and rear Dana 44 axels from a 1978 Scout II with an aussie locker in the rear axel. It has a SOA lift and is running 33x12.50 tires. The previous owner was trying to make it a rock crawler, and changed the gears to really crawl.

At the present time, in fourth gear I am running around 55 mph or so at 3000 rpm. This is really not suitable for my use of the Scout, which is mostly street driving with occasional light trail riding.

What gears should I look for to be able to run around 65-70 mph at 2500 rpm (if possible)? I am planning on replacing the r&p's and basically rebuild the axels this coming winter.

Thanks,

andy
 
I have used this website for years. It lets you do two seperate set ups side by side for comparision sake.

gear ratio calculator

I run 33 inch tires with 3.54s and I am very happy. If I spent any time off road with this truck, I would consider 3.73s. I hope this gets you in the right direction.
 
I would determine exactly what ratio you are running and then go from there. Ring gear should have some numbers on it when divided will yield the ratio.
 
I would first find out what gears you currently have. If you're lucky and gain access to see the gears in the diff's, they usually have the gearing info stamped onto the side of the ring gear and/or stenciled on the machined face of the pinion gear

fyi - for those 33" donuts, you be fine with 4.10 gears. I ran that setup for years in an ole 90 Bronco that I used to have. You could also get away with 4.56, but a slight pig more on gas compared to the 4.10
 
You are probably close to 4.27 gearing. Mine with 30" tires and 4.27 would give me engine revs around 2,800 at 52 mph.

I forget where the split is, but somewhere around 3.73 you need a different case when changing gearing. So going up to taller gears for you May need more than just a r&p. There should be an id tag on the differential that shows the gearing, other than that there will be numbers on the od of the ring gear. With those tires and taller gears, you might find yourself using 1st more often.
 
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