[Yukon Jack]

I swapped a SM465 4 speed into my 69 K20 to replace it's three on the tree. I was told there was a chance the bellhousing hole was slightly different for two different transfer cases but since than I've heard that they are the same. I used a different bellhousing so I never had to figure out if there was a difference.

If you swap transmissions and are staying manual, you will want to get the adapter and coupler sleeve that goes between the transfer case and the new transmission. Your transfer case will probably be an NP205 from the factory and it shouldn't be too difficult to find an SM465 and proper adapter. If you can get a picture of your transfer case we can confirm. There is a slight chance you might have a Dana 20 transfer case.

Expect to pay $100 to 200 for the tranny and adapter. You can often get a complete SM465, adapter, coupler sleeve and NP205 for about $300.

If you have an NP205, the length difference between the three speed tranny and the 4 speed is made up by the adapter so you shouldn't have to move your transfer case crossmember or mess with your driveshafts.

If you have a Dana 20 and you swap to an NP205 you will need to drop your existing transfer case crossmember down 1".

Nothing wrong with the Dana 20 but if you have one, now would be a good time to swap in a complete NP205 and SM465.

Power steering is pretty simple to add. You'll need a 4wd power steering box and power steering pump. If you get them off of the same donor vehicle you won't have to worry about whether the ends are correct. I put one in my 69 K20 from like a 78 K20 and it was an easy bolt in swap.

I'll let someone else speak about the power brake booster swap.