auto trans to manual swap

[justin4260]

I'm thinking about doing an auto to manual trans swap eventualy. right now I've got an auto th400 with the 350 small block bored to i have no idea po (-_-) anyways I'm looking to spend as little as possible as I'm 17 and only part time job on top of school. id like a 5 speed but 4 or 3 works for now i guess later on i can change it. what all does it take to do the swap beginning to end? i know you need a small gear size rear end, pedal assembly the high hump cab floor clutch master cylinder, new drive shaft stuff like that. whats the best transmission for my money thats fairly cheap and easy to install on a 350? best rear end? drive shaft? is there a kit that includes EVERYTHING needed to do the swap or a place i can get all of it at?

[Bladeboy1998]

I'm also interested in this

[notsolo]

I don't think there's a kit, this is a 1 off because so many different ways to go. I am going with a 3 speed Saginaw ( Out of a 69 nova, has synchromesh ) replacing Th400 ... Bought a clutch pedal here off the 4 sale forum. I already have the 3 speed and bell housing, will need to buy or cut driveshaft. Its all a matter of preference, and what you can find and afford.

[volksworld]

to do it stock style you would need the crossmember that the original bellhousing bolts to...but that is not a necessity if using a car-style 4 speed as you can use the automatic rear x member and a rear mount on the trans...and i doubt you want a stump-puller truck 4 speed...also you dont need the hi hump cause that was just to clear the huge trans,a saginaw or muncie fits under the regular floor...unfortunately a good muncie will cost over 500 bucks at the least...and a good shifter...you also need pedals, all the clutch release linkage and the ball on the side of the block that it pivots on.. and the bracket on the chassis the other end bolts to...flywheel,clutch,pressure plate,throwout bearing and fork...my starter is different cause it bolts to the bellhousing instead of the block but i think there is a certain diameter flywheel that lets you use your existing starter...hopefully someone that knows more will help here...the driveshaft will be a different length and use a different yoke where it slides into the back of the trans...perhaps a wanted ad in the classifieds here will find someone who just put in an auto or buy a wreck or a rotbox and part it out yourself... personally if i was 17 and working part time i'd leave it an automatic...then again if i was 17 i wouldnt take my advice

[enaberif]

Best and easiest option if you want manual is the SM465. There are a ton of them around and take the least amount of work.

You also didn't say if you have a 2wd or 4wd as that will also play a large role.

[justin4260]

can i just pull one off any car pr does it have to fit a 350? i make plenty of money to do it and 500 for the transmission is what i was expecting. the new ones i was looking at were 1500 to 200o just for the trans. i was jut gonna save up a few months and do that but id rather not if i can send a few hundred

[justin4260]

its a 2wd

[outdoorsman310]

I just did this to my 1970 c20. this is for a sm465. Definitely worth it, but my th350 blew up so thats why I converted it. I do not know if the auto trucks had a provision for clutch pedal installation, but mine was a 3 speed originally. If there is a junk yard around with some of these trucks that will help alot.

I will assume your truck is the same as mine and your engine is in the right position. I got most of my parts from a 68 c20 with leaf springs. It was probably a longhorn.
Stuff that bolts to the engine- Bracket for z-bar ball stud, it is easier if there are 2 holes in the block for it to mount. flywheel: make sure you get the correct flywheel for your engine and bolts- not the same as flex plate bolts, clutch kit with pilot brg, pressure plate, disc, throwout brg, alignment tool and bolts for pressure plate. if you have the huge stock starter, and got an I6 bell housing it won't fit in the bell, so you may need a starter with a smaller nose cone. Idk if what the v8 trucks used.

Get a truck bellhousing, transmission, V8 crossmember, and bolts. The center hole in the bell has to be the right size and is a tight fit. you may need bellhousing bolts, clutch fork, bolts for transmission to bell. If your trans is from an I6 truck, you need to bend the shifter so it doesn't crash into the dashboard. driveshaft with a slider in it and all associated hardware. you can not use a slip yoke on the sm465 because the u joint bolts to it. you might need to make a crossmember to hold the carrier bearing if you got a driveshaft from a different length truck like me.

You need a clutch pedal and complete v8 bellcrank (Z-bar) assembly. if you do not have the frame mount for z bar you need that also.
you might need some wires and connectors for the reverse light switch. I am probably forgetting some things. also sorry if this was jumbled together and hard to read.

[57taskforce]

The auto trucks should still have the hole in the fire wall for the clutch linkage and the auto brake pedal will easily accept the clutch pedal. You should be able to get all the clutch related parts from the for sale section here. Just watch the board for a manual truck part out. As for the trans I'd shove a 465 in it. Bomb proof and ultra reliable. They are a dime a dozen.

[Longhorn 70]

My truck was originally a TH350. My Uncle Frank, R.I.P., converted it to an SM465. Great transmission. The problem the truck had an Olds 400 and was there wasn't a provision for a crossmember installed under the bell housing for the trans mount. We put in a trans mount that bolted to the rear of the manual. It was always breaking. The pedal was easy to install from a donor truck.

I bought the truck in 82 and converted it to a TH400 in 88 to get away from the trans mount breaking. Around the same time I built an Olds 425 for it and it has been great since. About 2 years ago the Olds bit it and it's now a boring SBC.

The manual was MUCH stronger than any auto I've had in it. It was also noisier. I like the auto but truly miss the 4 speed.

[GASoline71]

Also depends on if you want a "truck" transmission or a "car" transmission. If you're looking for brute strength and stump pulling, then an SM465 with granny low. Great 4 speed for these workhorses. But if you're builing a performance rod out of your truck, you'll want to find an M421 or an M422 or an equivalent. Like a T10. These are usually found in decdnt shape in jumkyards.

If you want a cheap 5speed you could go with a T5. There is a build thread somewhere in the engine and drivetrain section of the forum on how to install a T5 into one of these trucks. But be cautioned as the T5 is not a heavy duty transmission. But can survive in a lower HP and TQ application.

Gary

[54belair]

There is no kit that Im aware of. I have (am doing) this in my current build. Im using a Muncie 4 speed from a chevelle, using a 3.08 rear and my engine was built for low rpm torque rather than high end hp.
You will need clutch pedal and linkage, frame mount bracket for cross arm, cross member for trans. and possibly a drive shaft built. You Wont need the high hump you mentioned. I have some pics in my build thread. The biggest problems I had was the exhaust. Never did find headers that would work well, ended up going with old style ramhorns.
I built my truck for occasional cruising and wasn't interested in a "hot rod". I used the 3.08 rear(coupled with the Muncie which has a 2.54 low gear) I should get reasonable mileage and reasonable street performance.
If you want to race from street light to street light--don't use the 3.08 rear. (use 3.73)

[markmdz]

yep, i'm subscribed.

I've been looking to do something similar as my C20 already has a 4-spd, but it's the stump-puller, so it's not a good daily. (BTW, not to get off topic, but can someone tell me what tranny this is?)

I just got off the phone with a shop here in CT that sells fully rebuilt, custom built T5's that are [claimed to be] built to up to about 800hp.

I had looked into NV3500's as well, and have always liked them in the truck's I've driven equipped with 'em.

For those that have done a 5-spd swap (from auto, or from 3/4-spd) can you post up your approximate all-in cost and what you swapped from/to?

[57taskforce]

If it's a 4 speed it's either an sm-420(67) or sm-465(68-72)

[GASoline71]

I wouldn't tow or haul with a T5. Handling a little more HP is one thing... but handling TQ is another.

Gary