bought a dodge 318/727 combo for the jeep!

black87yj

New member
ok, i went and did it now. i got a 1979 dodge shortbed truck with the 318/727/203 setup. now i need to see if the 231 will swap out for the full time 203 ? is there a boneyard special drivers drop tcase that will bolt up thats better than the 231? maybe a fixed yoke type ? the engine is good the transmission strong.needs carb work and some cleaning of the vac lines. someone said there is a np205 that is drivers drop out there ? (gear drive and fixed yoke !) any help is appreciated.
:)
 

Anything is possible, depends how much money you want to spend.

I am assuming it is for 89 yj with stock axles (drivers drop) I would just re-use your 231. actually I would also consider looking for a 231HD or a 242 for the 6 planetary gear set opposed to 5 and the thicker chain. I know a number of people running V8's with stock 231's and have no issue.. if anything your axles will be your limiting factor.

The tf727 is a great transmission, nearly bullet proof, the 318, honestly I wouldn't bother. that motor puts out around 150 hp and 235 tq, which is fairly close to what a stock 258's 112 hp and 210 tq. And you will still have an inferior emissions system and problematic carb.

If it were me, I would build a 4.7 stroker, find a 4.0 mfi, get as much wiring as you can, bolt that to the tf727, use a 4.2 crank and stroke the motor. Should put out about 200+ hp and 300+ tq
 
ya, i have a 91 cherokee to donate a 4.0 and my 4.2 block. maybe down the road i can put together a stroker. i was happy with the 4.2 in my 87 yj, but could see a little more power. i have a np207 in my wrangler now, a cherokee 231 and my son has a yj 231 thats stuck in 4 hi so maybe a good time to swap and do a sye. looking for a explorer rear axle down the road too....$$$$$$ lol. got the 318 donor truck for $250.00 an was cheaper than any 4.2 s i have found. i dont want fi. i'm a dinosaur and like my carbs. did motorcraft 2150,nutter and ign mods on my 4.2 and it ran sweet till it dropped a valve. maybe i,ll see what the axles are like under the donor , but i'm betting nothing to get excited about. (full time in all)
 
ok found alot of info on 318 swaps on some other jeep sites. the fact is its doable and not as costly as some fear. (bought truck junked it and got a 25 dollar profit to start ) my motor and transmission were both shot so i'm ahead this way. i,ll take pics if anyone is interested.
 
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