from what i know.. 3 basic versions..
1-early models had a 1" adapter plate...
2-later models out of full size jeeps had the 5" spacer.. V8 version
3-later models behind I-6's had a shorter adapter.. not sure on length..
all three could mount up to the same bell housing.. amc T-15
i have heard that the difference between the I6 and V8's where this way to keep drive shaft lenghts the same.. dont know if this holds water.. just what i have heard..
t18's that came in cj's from 71-76 had the 4:1 first.. the 77-79 version had the 6:1..
and all other versions that i know of came with the 6:1 first..
was also offered in 80 & 81 j20's.. but the output is different.. was round for the np208.. so its not much good.. since it also had a 9" output shaft..
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