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1970 Muncie 4 speed conversion

like2drive

Well-known member
Joined
Jun 9, 2004
Messages
149
Location
Lincolnton, NC
Corvette
1981 beige
I'm soon receiving a 1970 Muncie to convert my 1981 TH350C automatic to a MUCH more pleasing manual transmission. I already have some parts out of a 1979 in a salvage yard:; Bellhousing w/fork installed, crossmember, starter, (supposed to be different for manuals) driveshaft, (for modifing), flywheel, brake & pedal assembly (w/neutral switch & brake light switch) , Z pedal bar, and the clutch rod (that goes through the firewall). I also have the clutch-pac but will probably purchase a new one with roller throw-out bearings.
I know the 1981 manuals were Borg-Warner, (wasn't they?). Should I expect the 1970 Muncie to be a bolt-up? an easy replacement for the BG? The automatics have a crossmember that bolts up to the frame, unlike the manual chassis, can be moved forward and rearward. I concerned about the stick lining up exactly in the console.\
Ok, now I'll sit back for the always great responses from the original "know it alls", as you really do.! thanks Jim
 
Wait until you see the trans before you get the new clutch disc. Some have a 10 spline while others have a 26 spline input shaft. Either (B-W or Muncie) will bolt to the bellhousing and the shifter will end up in the same place. What makes a Muncie a Muncie is that it was built in the Borg Warner plant in Muncie Indiana. There really isn't that much difference externally in them, demention wise. In fact the Hurst shifter installation kit for the Comp Plus 4-speed shifter is the same part number for both B-W and Muncie transmissions.

If you stripped all of the standard trans stuff out of a '79 you should have all you need to install the trans in the '81. I can't answer the crossmember question. Never done this swap before. Don't forget to put a pilot bearing in the rear of the crankshaft. The roller type used in Chevy trucks and available at the dealer or Summit or about anywhere is the best way to go.

Tom
 
auto to manual

Thanks Tom for the valuable imput. I have received the Muncie (1971) and it appears to be a jewel. it does have 26 spline and it does line up with the bellhousing. That was very interesting in finding out that a "Muncie" is actually a Borg-Warner! No wonder they match. I've been busy cleaning up the parts from the salvage yard, & painting w/a rust-preventive paint. taking it slow, hoping to have all the details accounted for before I take it to the shop that will make the exchange, or perhaps I'll tackle it myself if I can get a building to work in. thanks again, really.
Jim
 
The 26 input is the heavy duty one . The 10 spline was for lighter duty applications.
 
Jim
bolt the belhousing up to your manual trans.....then measure from the front edge of the belhousing to the center of the two trans. mounting bolts and it should be the same as the auto. trans measurement.... the frames on the C2 and C3 Corvettes were pretty much the same for both the auto and the manual....If you don't pull the motor ,,,you will have to pull the distrubitor so you can tilt the back of the motor down to get the trany out

Mike
 
Another thought is to match the Flywheel and the Starter ;)

Bud
 
trans swap

Thanks mike,bud,tom, for the info. I'm still gathering parts and better insight for the task...I hope to have everything accounted for before starting. About tilting the engine, the friend I got the trans. from had a problem installing his new one perhaps because they didn't tilt the engine. But I was wondering, as far as removing the old automatic, I'm probably going to take the crossmember out (4 bolts), so wouldn't that eliminate the tilting necessity in the removing? maybe not. thats a close fit between the firewall and bellhousing. thanks again.

What electrical work will need to be done? The "Vehicle Speed Sensor", the ECM, the back-up /neutral safety switch....won't they all have to be "revised"? The automatic has the BackUp/Neutral wiring together in the console, but the manual seems to have two different wires....somehow they will have to be spliced and joined. I might cut the umbilical cord to the ECM!
Boy, this is a tricky!:W
 

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