axle swap

[derbydad276]

I'm thinking about switching out my rear axle ... and using a axle from Cherokee to get a higher ration and upgrade my rear brakes 

 

currently I Have a 3.90 in the original axle 

Cherokee's give me the choice of 3.07 and 3.55 

with the 3.90 gear ... I calculate 2100 rpm gets me 45 mph with a 28 inch tall tire and the engine sounds like it likes this RPM 

with 3.55 gears I'll get 50 mph 

with 3.07 gears I'll get 57

 

2500 rpm will get me 68 mph with the 3.07  which gets me on the interstate 

do 230 engines make enough power to hold the speed ?

[Adam H P15 D30]

I run a 3.0 ratio in my 49 with a 230 which was too tall with 28” tires, perfect with 26” tires. I’d go with the 3.55 if you’re keeping the taller tires. 

 

Adam

[hotrodbob]

I had the 3.90 rear with a built 216. Ran great down the freeway with 235/78 x 15 tires.. Didn't have a tach, but would run from LA to San Francisco and get 20mpg at 65 mph. Taller tires are cheaper and easier than a rear end swap.

[The Way]

I have a 230 , not rebuilt but great compression, with a single barrel carb, 27" tires and 2.79 gears. I made most of the 400 mile trip to RI at 75mph at 2600 rpm and could have gone faster still. I now have dual carbs, 3.25 gears and 28" tires. I regularly go 75 mph at 3300 rpm with more left. The 2.79s were great on the highway, but kinda slow compared to modern vehicles leaving when the light turned green. The 3.25s keep me up with city traffic and I end up with 17-18mpg on the highway. I have a 3 speed manual with fluid drive.