83 cj7 manual to auto

had this cj7 for 18 years, with the last 8 parked in the garage holding up boxes. always going to put a new engine in and drive it but life (kids,job, WIFE) always got in the way. well, my son turns 16 in a week and we have been working together to get the cj road worthy again. this is a budget build with parts sourced completely from craigslist! stock engine is 258 six, tranny is t-176 4 speed, and power steering. the jeep has an older 2 1/2" lift and good 32" bfg m/t's. the engine was going through a quart a day. thats why i parked it. while looking through craigslist 2 days ago i found an engine for sale: 82' 258 with auto $300.00. called the guy and he had just put it on the list and still had it! made an appointment for the next day,and my son and i drove 2 hours to look it over. we were surprised to find the engine still in the jeep and hooked up. started and ran well! really, really well! drove around the block a few times and bought it. the seller had a 5.3 chevy sitting there for a swap or i would have been a lot more suspicious. previous owner had stripped all the emissions stuff off of it,(no emission checks here in kansas) had replaced the carb with (i think) an older non computer carb,  an hei unit, an aluminum valve cover, and a new starter. I am as pumped as my boy! *** engine has the 999 auto(i think) or maybe a torqueflite. i got the auto radiator and rear driveshaft with the engine and when we pulled it the fluid looked very good and it had shifted good  too. what is the cheapest way for me to go forward with this project. can i just pull my old engine, tranny, and 300 t-case (donor engine had a 300 also but the guy kept it) slap t-case on new engine, put in an aftermarket shifter and go? or do i pull the old engine and mate the new to the t-176 and 300 t-case. i like the manual but a new driver might do better with an auto, for a while anyway! the determining factor for this swap however, will be 1-cost, and 2- time factor. i have read jp for 10 -12 years now and i trust your opinions, so any tips and/or suggestions will be very valuable to me. thanks!  

Bump for some help