Sm465 swap

[379redneck]

I am thinking about replacing my th350 with a 465. I have had bad luck with automatics and want to try a stick and I like the low gear of the 465 because I wheel my truck a lot. I read that the 350 and 465 are the same length, is this true? I don't want to have to mess with my driveshafts. Are there any differences between the different years of the 465 that are better than others? What will have to be changed to do the swap? I k ow I need to cut out the floor, pedals, column, fly wheel, block off the tranny lines. This will be my first time swapping to a stick in one of these trucks so any help would be great. Thanks
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[b454rat]

It's easy if you have a complete donor truck. I did one, but can't remember all the details. But the best 465 (IMO) to use is an 85 and newer. I prefer a 205, just like having the peace of mind that a chain will snap, or the shaft pull out. But without doing crazy stuff, the 208/241 will be fine. Also they had a hydro clutch, which is nice and smooth compared to a mechanical setup.

But you will need, the tranny/t-case, possibly crossmember, clutch pedals, steering column, and depending what bell housing, the linkage or hydro stuff, clutch assembly, flywheel, and again depending what t-case, a rear driveshaft.....

[379redneck]

If I keep the 203 would the driveshafts I have now reach? The truck is lifted 6" and the front driveshaft was lengthened 2" and rear is stock. I don't want to change the transfer case because I don't have that much money and I just bought a twin stick for the 203 so in just gonna keep till it blows up and then get a doubler
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[b454rat]

So you want a stick with the 203? That will be difficult since GM only used them in for 3 years. I've seen two. Either need to find the factory setup or get a late model 465/208 or 241 adapter, change the input in your 203 to 32, then drill and tap the front of the 203 to match the pattern of the adapter. Not sure on the shafts....

[jjzepplin]

Off Road Design make a doubler kit for your 203. If your truck is in running condition, Then begin to look for your complete setup. As stated above a complete donor would be your cheapest bet. If you wheel a lot your going to want the 205 for sure. I have the doubler 203 going into the 205 and a 700r4 auto. This gives me the super low and overdrive. It does however sound like your not getting out of this cheaply.
What problems are you having with your auto? They have been good to me but then I rebuild my own with B-M everything.

[burnin oil]

Advance Adapters sells the 465 to 203 adapter. I have seen a couple of the factory adapters and they are rare. No way I am letting go of the one I have. Anyways on to the driveshaft question. If your shafts already fit then they will after the swap. The Tcase adapter takes up the slack and mounts the tcase back in the same place on the crossmember. Both trucks I swapped out autos for sticks were this way. If you are running the stock driveshafts with a 6" lift you probably need a new shaft anyways. The power the stick will put to the ground combined with limited spline contact on the stock shaft will definatly have a shorter lifespan.

On a side note. When I swapped out the th350 in my old blazer with a 400sb I went from 8MPG intown and 6MPG interstate to 12-14 range combined. That was with 3.07 gears though. Be interesting to see what yours does. good luck.

The swap is a bolt in. You need the entire pedal assembly under the dash. This bracket holds the vacuum booster on the other side of the fire wall. Also need the zbar and clutch linkage. Only other thing is to bypass the neutral saftey switch (jumper it by twisting the wires together) and change the plug on the reverse lights. Everything else is obvious like cutting a hole for the shifter and the clutch linkage rod (or hyd cylinder if using a late model doner). Usually the firewall is premarked for the clutch linkage. The only thing that is difficult is the Zbar is usually riveted to the frame, atleast the holes are usually already in the auto trucks frame.

[379redneck]

My auto is working ok, for now. It's just leaking like crazy. It lost 1/2
Gallon of fluid in a week and now it's even worse and it's leaking from somewhere else pretty good too. I wouldn't care if it wasn't for the fact that I just took it out to fix
The same leak. The big concern with is that its been flushed 3 times since I got the truck because of water and I don't want to pay to have it fixed for it to blow up. Only my rear driveshaft is stock. I'll look around at the junkyard to see what I can find. I dont ehat my mpg change will be because i never checked it with the auto and its leaking tko much for me to find out now. Thanks a lot
for the help
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[burnin oil]

Shoot me a pm if ya need some help with the swap. It isnt that hard if you have a little more than basic hand tools. Done it several times on the 70s version of your truck.
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[379redneck]

Do I need the zbar if its the hydraulic clutch?
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[burnin oil]

Nope. Zbar is the mechanical clutch pivot. Hooks to the frame and engine or bellhousing. It would be one or the other. Dint forget to verify the spline count going into your tcase. Probably need to swap that gear out to match the 4spd.
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[b454rat]

I want to swap mine from a stick to an auto, but I need to go with a 400/205. Also gonna be swapping the 454 out of my car into the truck, so need something strong....Not sure how far you are from D's, but they might have something there....

[379redneck]

I'm right next to Wilkes barre if that helps. I found one at Harry's today that was the hydraulic setup but it wouldn't go into first gear
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[b454rat]

Was it 4wd? I might swap to hydro while I'm looking for 400/205....I wouldn't worry much about not going into gear. Sometimes they do, sometimes they don't. All depends if the gears are lined up inside. I like to leave mine in gear, usually 1st aka low, and sometimes it won't go in. If you shift thru the gears then try for 1st again, usually goes in. I'm barely an hour from D's, maybe tomorrow take a road trip and check out the inventory....

[379redneck]

It would have been 1st according to the shifter, so the second gear. I went thru the gears a few times and that was the only one that wouldn't go in. Maybe Friday ill grab it if its still there if I can't find anything else
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[burnin oil]

Pretty common actually. You could always pull the PTO cover and have a look. These trannys are pretty beefy for the application and rarely break to be honest. The same trans was used in 2.5 ton trucks with the addition of a larger input gear and rear Ujoint flange. If the rearend is off the ground you may be able to push the clutch in and spin the output (tire, driveshaft, yoke, etc) and get it to align for the gears to slip in. More than likely it is just sitting in a place where the syncro just cant be aligned due to being stationary.

[379redneck]

I went back to check it out today and its actually low that wasn't working. I tried turning the back tire while my friend tried getting it into gear and it still wouldn't go into low
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[b454rat]

Its' not a big deal if it won't go in every gear. My truck is the same way, even my car won't go in every gear all the time. Did they have any 4wd with auto's? I need a 400/205 combo....

[379redneck]

I think they had a couple 400s but I don't know if they were 2wd or 4wd
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[b454rat]

I have a 400 that will work with either, 2wd or 4wd, but for 4wd it needs to be roughly 85 and older....