4 speed swap!

[67chevy_hotrod]

I plan on putting an sm465 or something similar in my 1969 longhorn Chevy. It's got a th400 right now and I just love a standard vs an auto. Anybody that's done this swap please pitch in advice! Also does the cab floor hump change from an auto to a 4 speed?

[Gmc.guy]

I would try to find a donor truck for all the parts you have to chase like petals, z bar and linkage. and bolt in floor hump. These trucks also had an sm420. Almost same trans as 465. Look for tail shaft mount crossmember trans Not bellhousing mount. Don't forget pilot bushing in your crank, I've done it. Just winging things that I remember. Lol. You might need to go to a 2 piece driveshaft with slip and carrier bearing in middle. I would go with 78+ for better shifting I'll let you know others as I remember.

[Gmc.guy]

You can trim the low hump out and bolt the high hump after drilling some holes around the lip

[67chevy_hotrod]

Originally Posted by Gmc.guy

You can trim the low hump out and bolt the high hump after drilling some holes around the lip

That was my plan of attack for that but where can I find one? Just cut it out of another truck or lmc type deal?

And thanks for the advice it's all appreciated! It's tough to find a donor truck for that kind of stuff that hasn't been totally torn apart around here!

[dan42]

Look on the parts board, they are always turning up there.

[El Dorado Jim]

I thought the turbo 400 trucks had the high humps,one of my previous trucks was a 3/4 ton gmc 2 wheel dr with a t400 had the high hump,. also, in '69 is when gm started using the sm 465,they are a better trans...anything from '69 up will fit, if you use a '73 or newer you have to use the aluminum bell housing,or you need to drill out two of the cast iron bellhousing holes... just need to use the throwout fork ball out of a 67-72 in the bellhousing, that way you can still use the 67-72 fork...I agree that it is easierto find a donor truck, but that may be hard to find, you can hit wrecking yards for the parts...

[Gmc.guy]

Originally Posted by 67chevy_hotrod

That was my plan of attack for that but where can I find one? Just cut it out of another truck or lmc type deal?

And thanks for the advice it's all appreciated! It's tough to find a donor truck for that kind of stuff that hasn't been totally torn apart around here!

You should be able to just unbolt high hump and cut yours out. Shouldn't have to cut anything off donor. There is a bunch of threads around for that. I have a 71 here with everything. I'd give away.

[67chevy_hotrod]

A 71 with all the 4 speed parts?! Define give away

[Gmc.guy]

Come and get it free. Haha. You could get a parts truck I bet for less than coming to get them. With a parts truck you get the springs and linkage, all the little things You could get a square Body and swap trans and flywheel. Find another similar to yours for a petal setup and high hump. Mismatch parts There's a light green /dark green plug on top of trans for backup lights too. Some people just pull the little pin out of the shifter handle and take it out. Or find a manual one

[Gmc.guy]

I would spend 1000$ on a parts truck before 1500$ worth parts. This one was a farm auction truck. Lots of good parts I think about 250$ I spent. Knocking 350 basic truck leaf spring 4 speed

[Gmc.guy]

I used the power steering box pump and brake booster on my 69. Also have the front crossmember for disc brakes later on.

[Gmc.guy]

This truck was great value for parts. It had nice quadrajet, rad. Fuel tanks (5 of them) propane setup. 2 lp tanks are 8 feet long, power steer and brake parts 3.73 diff. Nice steel bed floor All kinds of stuff. I have the room and will use parts off it for years. At least you can part or whole sell what you don't need or start another project. Haha