so i got a 47rh for free. overdrive is out other then that its good. i have read almost all the posts about this swap but i have some questions of my own.

do i need to change the dipstick?

did the 2nd gens come with a lock up switch? what are you guys using?

how much is the difference in length? i might lift my truck a inch or two so would that make up for the length?

same gear ratios right?

i have a 91 so i have no electronics. i dont need a TPS or any of that overdrive crap you 91.5-93 guys have?


thanks alot!

 

No 2nd gen came factory with a lockup switch..... they had a O/D lockout switch on the dash and that was it. Most people who bought the trucks did'nt know what lockup was.

Most of the time when doing the 47rh conversion in a 1st gen, the switch is monted somewhere on top the dash (like JD730's) (seen his truck in person).
and has to be manually engaged when you want lockup, it doesnt come in automaticly like 2nd gen will do, probably could make it do everything automaticly with some extra wiring. IDK

There are two common Dodge 4-speed automatics: The nonlockup 518 and the lockup version designated 618/47RH. The 518 was used prior to computer controls until 1994. Everything ’94 and newer has the lockup torque converter (618/47RH). The gear ratios of each of these transmissions is the same. That was copy/pasted off another site.

BTW, the 47rh needs a aftermarket valve body setup to be able to lock it up in ALL forward gears, Which is where it gets fun

 

Well since you are going from a 727 to a 618 you will need a shorter drive shaft no matter how much you lift it. There is a 3" difference between the 727 and 518 drive shaft, when you put the 618 in you will need to make the holes in the trans mount approx 1" longer (according to talking with JD730). I believe you will be able to use the 518 drive shaft on the 618 but the 2nd gens used a yoke in stead of the slip joint with a u-joint on the transfer case. Someone please correct me if I'm wrong.