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Old 02-03-2009, 12:47 PM   #1
Eturnit3
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The Ole 3 speed swapout, 72 lwb 4x4

Ive done some searching and saw there are some other threads similar to this but I have some different specifics, Im running the stock 3spd (now converted to floor shift, sloppy as hell) and its not a bad tranny, sucks for freeway but I dont tour much with it anyways. My question is, has anyone converted to floor shift and if so, did your knuckles hit the dash/seat when shifting? Ive tried shorter shifters which leaves me leaning over to shift, Ive made my own with custom bends, and I cant get the damn thing to not be sloppy. The conversion kit was a hurst (from summit) . Ive wrestled with the idea of swapping out for either a t400/t400, m21 or m22/208 but Ive heard its an abortion involving custom drive shafts and possibly cutting cross members. Any recommendations?
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Old 02-03-2009, 01:36 PM   #2
mrein3
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Re: The Ole 3 speed swapout, 72 lwb 4x4

Other than losing a great theft deterrant because most of the car stealing idiots can't drive a 3-on-the-tree, I'm VERY happy with my truck after swapping out my 3-speed manual for a th350.

Nobody but me could back my boat down the landing, nobody could drive it for me, and when I was driving it the stupid linkage would lock at the WORST possible time.

A 72, 3-speed should have a NP205 transfer case. If it does, ANY th350/NP205 out of this vintage truck is a direct bolt in.

Back in the day GM made up the difference in transmission lengths between th350s, 4-speeds, and 3-speeds in the transfer case adapter. Shorter 3-speeds have longer adapters while longer th350s have shorter adapters.

What does all this mean to you? Well all you need is a th350/adapter/NP205 out of a 67-72, a different (auto) steering column, and the shift linkage to make the swap. The driveshafts are the same and the crossmember doesn't move. The speedo output is in the NP205 which is in the same spot after the swap so your speedo will stay correct (or incorrect if it currently is off).

You need a radiator with a cooling/warming tank in it. A set of hard lines to/from the tranny, and vacuum to the transmission.
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Old 02-03-2009, 02:19 PM   #3
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Re: The Ole 3 speed swapout, 72 lwb 4x4

I changed my three on the tree to a four on the floor with a sm465. It's basically a 3 speed because of the granny gear but it was a great switch. Mine is a 4x4 so I needed to mate it to a 205 x-fer case with the correct adapter but it was really just a bolt in change.

If you do go with a sm465, 4x4 and 2wd trany's have different shifters (even though the trans is basically the same) because the trans mounts in different position on the frame. I believe the 2wd shifter is longer and the 4wd is shorter. Also, the 2wd model has a different output shaft than a 4x4 model trans.
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Old 02-04-2009, 07:01 AM   #4
special-K
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Re: The Ole 3 speed swapout, 72 lwb 4x4

I`d find a 4spd/205 unit and keep the clutch.That`s exactly what I have for my`71 K/10.
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Old 02-04-2009, 12:07 PM   #5
Eturnit3
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Re: The Ole 3 speed swapout, 72 lwb 4x4

Thanks guys I highly appreciate your input, I certainly wouldn't be opposed to a 4spd as long as it wasnt the granny 4 speed. Im kinda liking the idea of not having to muscle my clutch anymore. The linkage for the clutch relies on one major pivot point between the frame and the block, and that seems to be the weakest link. The notch on the frame that holds the linkage straight is a little wallered out so my clutch pedal seems to stick about half mass on release. Ive even fabricated my own little retainer clip out of a large washer but it didnt take long before it failed as well. I will be doing some research this weekend to find out if it is in fact an np205 transfer case, I will also take some pictures to further clearify. Thanks again for the input guys, I will photo document everything I do to this truck.
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Old 02-04-2009, 02:37 PM   #6
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Re: The Ole 3 speed swapout, 72 lwb 4x4

i have a question about your hurst shifter. when you say sloppy do you mean cheap piece o c---- or sloppy like the 3 on the tree. also is it the cheap indy shifter or a more expensive one? i like my tree shifter but it always feels like your gonna hit 2 gears at once.
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Old 02-04-2009, 04:56 PM   #7
Eturnit3
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Re: The Ole 3 speed swapout, 72 lwb 4x4

Quote:
Originally Posted by long69 View Post
i have a question about your hurst shifter. when you say sloppy do you mean cheap piece o c---- or sloppy like the 3 on the tree. also is it the cheap indy shifter or a more expensive one? i like my tree shifter but it always feels like your gonna hit 2 gears at once.
By sloppy I mean it has a ton of play in it. From REV to 1st, were talking knuckles on the dash to knuckles on the seat. Also the shifter I am using now I made custom. The Indy style shifter that came with the conversion kit, would not allow me to shift to any of the front gears (rev, 2nd) it wouldnt move far enough forward. Luckily I had a older hurst shifter with the same bold pattern and it was a long sumbich so I heated it with a torch n put a few custom bends but like I say, its sloppy. I wouldn't recommend the conversion. Its been awhile now but I think I had to modify/cut the mounting bracket too.
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Old 02-04-2009, 05:04 PM   #8
tkeduk8r
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Re: The Ole 3 speed swapout, 72 lwb 4x4

Hurst also make a "good" shifter called the "mastershift" if I remember right.. That one is a bit pricey, but those that I have talked to about it say it is worth the xtra $$$... I was going to go with tath mastershift in my 74 before i ended up getting a sm465 for free...
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Old 02-04-2009, 05:05 PM   #9
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Re: The Ole 3 speed swapout, 72 lwb 4x4

thanks for the answer. I've been fighting myself over that indy shifter. fairly sure i'd not be happy with one now.
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