Auto to manual conversion

[Diablo de la Noche]

I have too much time on my hands right now and things are going through my head, probably in the wrong direction.

My 700r4 is shot. I need a new one. $100 and I can swap it out, but, what about converting to a manual? How much has to be done? My 67 has a small hump, and all the shift linkage is gone from the column, so I figure why not? I know manual trannys better than I know autos, so the install shouldn't be too much of a stretch for me, and maintenance would be easier I think.

So what am I in for? Do-able or a real PITA? Positives and negatives?

[Trip59]

Just did mine, actually, just finished Wednesday night. I went from a long tail TH350 to a Saginaw 4 speed. I had to get a longer front shaft, as the Saginaw is the same length as a short tail TH350... yours will depend on the trans you pick.

I used an aluminum bellhousing from a 60's Chevy, Hurst Comp Plus kit. With my pick, trans mount swapped straight over, only thing I had to do was cut a hole in the floor and swap the driveshaft. If you go with a trans that needs a high hump, there are a bunch on the forum, I think wancosc356 has three or five of them listed right now, some other folks do too. I bought a clutch/brake assy off a board member, as someone hacksawed my clutch when they converted to an auto years back. wancosc356 has one of them listed too...

Biggest PITA was that I'm disabled (bad spine problems) and my buddy who helped has nearly as screwed up a back as mine and we did it on jack stands. Several beers and pain pills later, I had it in place. If you can beg or borrow lift use, DO IT.

When you replace the bushing/bearing in the end of the crank, be sure to use the freezer, it's your best friend. Spring for an ALUMINUM clutch tool, take the plastic one that comes with the clutch kit and chuck it as far as you can.

If it wasn't for the fact that I'm in such sad physical shape, it probably would have been a Saturday project. Took me a solid weekend worth of time, but spread out over two weeks so I could paint things, work at a slow pace, etc.

IMHO, can't beat a standard trans, I'd never drive an auto again if I had a choice, but, my 72 is now manual trans, manual clutch, manual brakes, manual steering. My HD is kick start, magneto, generator, manual clutch, so this is just a continuation of the anti-soft and cushy...

Trip

[LMN8UR]

Remember, Saginaws are only good to about 250 hp! (Speaking from experience X3).

Good Luck.

[Trip59]

Originally Posted by LMN8UR

Remember, Saginaws are only good to about 250 hp! (Speaking from experience X3).

Good Luck.

Debatable...

Also depends on the trans and how you drive it.

Trip

[katyjevoich76]

I want to put a sm465 in my 72 4x4 but i have between 300,and 400 hp 454 is ththe 465 only good for 250 hp ? Ive never had any trouble with a truck 4sp I thought they were pretty strong

[Beuford]

I went from a TH350 short tail to an MV3500. There are alot more things to change but I wanted overdrive. Hyd clutch and slide the cross member back. The 5 spd is the same length as a TH350 short tail but the front driveshaft yoke has to be for a TH400 because the tailshaft is larger than the TH350. But I didn't have to cut the driveshaft. I put in a high hump and the 4 spd hole is in the perfect location for the MV3500 shifter. I know alot of guys say they are weak but anything is weak if you abuse it. I tow a 24' toyhauler at about 6000 lb loaded. I have a Dana 60 with 4.10 posi and that takes some of the strain off of the trans. Works good and I like it. The engine turns 2500 RPM at 68 MPH. I got 16 MPG using cruise with just the truck no load when we drove to Cincinati,Oh about 390 mi.

[katyjevoich76]

are those made to tow in overdrive

[Beuford]

Originally Posted by katyjevoich76

are those made to tow in overdrive

I've pulled my toyhauler in OD on fairly level ground. I watch my vacume gage and try to keep it between 6in and 8in. If I feel like the motor is starting to lug I shift to 4th. It will pull pretty steep hills in 4th with the 400 cu in and the 4.10 rear. I shift to 4th if it starts pulling the speed down below 50 mph and 3rd if it pulls down to 40 mph.

[djinva]

[QUOTE=Beuford;3856115]I went from a TH350 short tail to an MV3500. QUOTE]


I am interested in going this direction as I also want overdrive. What did your trans come out of? How hard was it to install the hydralic clutch?

thanks

[Beuford]

Here is a Mirosoft Word Doc if I can attach it. It will answere alot of the questions with some pics included. PM me if you need more info and I will try to answere your questions.The trans was from a `90 Chevy.

Bob

[LockDoc]

Originally Posted by Beuford

Here is a Mirosoft Word Doc if I can attach it. It will answere alot of the questions with some pics included. PM me if you need more info and I will try to answere your questions.The trans was from a `90 Chevy. Bob

Attach the MS Word .doc file to your post the same way you do pictures.

LockDoc

[Diablo de la Noche]

Uuuh, yeah. So I guess it is a little involved. The PITA factor seems pretty high. I think I will stick to a 700r4 so I don't have to swap out the hump, driveshaft, brain cells, etc. Excellent information and I appreciate it. Got the information I was looking for, even though it wasn't the answer I wanted! Maybe on my next project, or this one when I'm better at it!

[Beuford]

Originally Posted by LockDoc

Attach the MS Word .doc file to your post the same way you do pictures.

LockDoc

Tried that it didn't work.......thanks. They PMed me their e-mail and I sent it straight to them.
Bob

[Shaky]

Originally Posted by katyjevoich76

I want to put a sm465 in my 72 4x4 but i have between 300,and 400 hp 454 is ththe 465 only good for 250 hp ? Ive never had any trouble with a truck 4sp I thought they were pretty strong

I believe the "465" is the nominal torque rating. My brother had a '68 C10 with a factory SM465 and 327 4-barrel. After the 327 was tired, he put a hotter 327 in there and punished that thing. The 465 never even got loose...

[eastcoastcivil]

Everyone here has changed from auto to manual.....I want to do the opposite, but can't find an auto tranny crossmember for the life of me.

[brans72]

Yeah I wanna go from 3 on tree to auto on the column. Brandon