Transmission swap suggestions (1 Viewer)

[Jim1968FJ40]

IH8MUD members,

I need some ideas and more comments. I am swapping a 3 speed behind a 400 small block with 425 horsepower for; (a) Muncie SM 465 4 speed or (b) Borg-Warner T-10 4 speed or (c) Tremec T-5 5 speed.

Will any of them fit correcting in a 1968 Toyota Land Cruiser without to much or zero modification?

Waiting thoughts, comments, and/or suggestions...

Thanks in advance...
-JIM

 

[65swb45]

What are you trying to achieve? Rock crawl? Highway driver? Overdrive? Planned tire size? Diff gearing?

Those should all be factored into a thoughtful swap.

 

[3_puppies]

X2 to what Mark stated above, plus what transfer case are you going to use? as the 68 1 piece transfer case will become a "split case" in no time

nothing will be a no modification swap, adaptors, drive shafts, crossmember, etc

 

[Jim1968FJ40]

What are you trying to achieve? Rock crawl? Highway driver? Overdrive? Planned tire size? Diff gearing?

Those should all be factored into a thoughtful swap.

My achievement is to lower rpms on the highway. I have 275/75/16 with the original gears at 4:11. Trying to keep the original transfer case if I can.

So, which manual trans would be best for my TLC that can handle the horsepower?

V/r
-JIM

 

[69LC]

If your goal is to reduce rpm then only an overdrive tranny will work. There were no OD trannies built to bolt up to the three speed case that I’m aware of.

An NV4500 will likely be your safest bet to reduce rpm and handle the power. You will have to use some adapter somewhere in the equation. If you’re set on keeping the old tcase it will need a beef up plate. I’m sure someone here knows where to find one.

 

[Jim1968FJ40]

I have research far and wide for a NV4500 Chevy 5 speed at a better price than 2400.00. I am interested in buying a NV4500...

V/r
-JIM

 

[pbgbottle]

Sm465, is what I run ,,it’s a v8 how high are your running rpms.
Lol
U may want an overdrive tranny I do wish I had an extra gear sometimes and I’m runnnig 37’s with the 4:11 gears. Stock 3 spd tcase

 

[pbgbottle]

The sm420 would be the easiest for fit and least epxpensive adapter one inch plate. Adapter to 3 spd. Tcase. I think EBI is still making the adapter plate kit. (Extreme Bends Inc )

 

[3_puppies]

IDK but how long is a NV4500? is length going to be an issue in a 40 series?
probably will matter where the V8 is situated in the frame?

 

[69LC]

A v8 is considerably shorter than the I-6. That leaves room to play with. Also, lots of people have swapped nv4500s in without trouble. If the OP isn’t going with a tall lift it shouldn’t be an issue. A CV rear driveshaft with the pinion pointed at the tcase would alleviate the issues of a shorter or higher angled driveshaft.

 

[mattcamp]

Jim, changing trannys will not be a bolt in with no mods while keeping the transfer case no matter what, but you could think about going to 3.73 ring and pinions to lower hwy rpm, then if you opted for the sm465 you would have a compound low and a hwy cruising speed. At least throw a case saver bracket on that transfer case so it has a better chance of not cracking, I don't know if they do much, but they are cheap and easy to install.

 

[Downey]

If you are interested in keeping your 3 speed transfer case, but believe your 450 h.p. will crack your transfer case (it will), then you need to look at ebay #254272333466.

 

[Living in the Past]

I would price what you will pay for a Orion case verses sourcing a split transfer case. 450 HP is a lot of power for a transfer that was never mated to half that at the factory. The adapter for transfer case is not cheap. Not as easy to find used a factory transfer case. Same with the Orion, that do not become available used very often. Doubt with 450 HP your not going to drive like grandma going to church on Sunday. If you don't mind changing transfer cases could probably pick one or two one pieces cases cheap ahead of time (seems when you need something you can't find it or price is ridiculous). I run only LC running gear but since your going with a non Toyota engine transmission could get a transfer case that bolts directly to the transmission to save the cost of adapter and gain length. Then switch to a Dana 60 rear axle with a centered diff.