4.0 swap tranny

[pearldrumbum]

I have a 88 4x4 w/ 2.9 that i am collecting parts for a 4.0 swap for right now.
I know that the M50D is the tranny i should use because it's stronger, but is their any difference if it was originally behind a 2.3? I'm getting the 4.0 out of an explorer with a bad tranny, and a friend of mine just wrecked a '90 2.3 ranger and offered to give me the tranny.
I know the gear ratios are different between a 4.0 M5OD and a 2.3 M5OD, but is there a difference in it's ability to hold up to a 4.0?
I'm hoping it will work because 1) its free, and 2) the gearing is better for stump pulling

 

[Sunk]

I think the bolt pattern is different between the two. If you really need to go on the cheap, you could use FM that's behind your 2.9, but don't expect it to hold up too long.

 

[pearldrumbum]

ts not really about saving money. Its just that the cheapest thing to find with a 4.0 in it is usually an explorer, and i'm only finding automatic explorers. I dont want to use the FM cuz i know it wont hold up very long.
I dont see anything in the tech library about m5od's having varying bolt patterns, im just wondering about strength differences between ones used behind 4.0s and ones used behind 2.3s.

 

[BlackBII]

2.3's and 4.0's have different bolt patterns, so you'll need an M5OD from a 4.0 Ranger or Explorer. They do exist.

If you need to, you can use the FM, I 've had one last for over a year behind a 4.0 on a daily driver. It depends on what shape it's in right now. (Not saying yours will last a year, just an example.)

 

[Sunk]

If you do use the FM, make sure at least do the 4.0 clutch upgrade, or you'll be dropping it to do clutches all the time...

 

[pearldrumbum]

Okiedoke, thanks for the info! Guess I'll just keep lookin...

Will i run into any problems if I get the engine from an automatic vehicle, and the tranny seperately? Are the wire harnesses or computers different?

 

[Sunk]

Yes, you need a harness and computer from a vehicle with a manual, hence why it is usually easier to get a vehicle with manual so you have all the little parts there.

I'd try to keep looking for a 5 spd explorer, or even a 4.0 Ranger would work.