My mom has an 82 CJ5 with a 4 in lift and 33's with a 360 in it and she gets around 14-18 in town id say. its real easy for that engine to push that light car around economilcally. Im not sure of her gear setup but it is the stock gearing. Having driven her car, id say go for it. You will love the performance and the gas mileage aint bad either. Hope this helps.
76' J10 with AMC 360
original brown paint
MODS= 4' superlift kit,Black diamond extreme terrain shocks 32in BFG AT's, Ramsey winch, KC 160w lights,Alloy rims, campershell,
K&N Filter, Custom 3" exhaust
Interior mods= Sunpro tach, clarion stereo, Clarion 6-1/2 coaxials, polk tweeters,two alpine 10" subs
Proud member of the "Creepers Jeepers Gang" of Durango CO, my home town.