Clutch Issues

[twoskies]

Hi

ive got a 1972 c10, from the factory it had a 350/4 bolt main with a muncie sm465 4 speed(pretty common) before i got it someone had stuck a 305 in it, it was junk, i pulled that motor asap, found a 350/4 bolt main out of a 1979 el camino ,10,000 miles, was going to put motor in today, found out the pressure plate would not fit, too small on the crank diameter, started measuring the clutch and pressure plate about 12 inches in diameter, checking with the parts stores they are telling me the diameter should be 14 inches, any help appreciated
also if anyone has factory parts numbers


also could the bell housing need changed or is it the same

i can look up numbers (id) if anyone tells me where to look


thanks

[LockDoc]

Originally Posted by twoskies

Hi

ive got a 1972 c10, from the factory it had a 350/4 bolt main with a muncie sm465 4 speed(pretty common) before i got it someone had stuck a 305 in it, it was junk, i pulled that motor asap, found a 350/4 bolt main out of a 1979 el camino ,10,000 miles, was going to put motor in today, found out the pressure plate would not fit, too small on the crank diameter, started measuring the clutch and pressure plate about 12 inches in diameter, checking with the parts stores they are telling me the diameter should be 14 inches, any help appreciated
also if anyone has factory parts numbers


also could the bell housing need changed or is it the same

i can look up numbers (id) if anyone tells me where to look


thanks

-
I'm not quite understanding what you are saying. The pressure plate bolts to the flywheel so the crank diameter doesn't have any to do with the pressure plate. Flywheel diameter does though. Do you have the flywheels and clutch assemblies from both engines? Does one of the flywheels have a dual bolt pattern for the pressure plates?

There are two different size manual trans flywheels, 153 tooth and 168 tooth. Do you know which one you have?

LockDoc

[twoskies]

Hi
ok, ive measured all pieces, the flywheel off the 305 measured 14 inches in diameter and where it bolts to crank was about 2 inches id
the flywheel off the 350 is obviously thinner because it was an automatic but the outside diameter is about 12 7/8 with the id on crank side about 2 1/2 inches

i dont have a flywheel or clutch or pressure plate for the 350
guess ill have to buy all the pieces, didnt know if the 305 pieces would interchange at all, they were new when i bought the truck

as far as the bell housing, if the 305 pieces were 14 inch diameter, any thing would work as long as it fits

thanks

[twoskies]

HI

the 305 had 168 tooth
the 350 had 153 tooth

thanks

[LockDoc]

-
If all of the parts bolted together on the 305 they should all bolt together on the 350. Sounds like you might have a 10 1/2" clutch but I don't think so if it had a 168 tooth flywheel. It isn't a big deal unless you are going to race it...... I would just bolt everything up to the 350 block the way it was on the 305 and go with it. If I'm missing something I hope someone chimes in and points it out.... You will have to pull the pilot bushing out of the 305 crank and put it in the 350 if it doesn't already have one in it.

LockDoc

[twoskies]

Hi

the 305 id wont fit the bigger id on the flywheel mount on the 350( 2 inch to 2 1/2 inch, im checking online and the part numbers are different for the years thanks

[LockDoc]

Originally Posted by twoskies

Hi

the 305 id wont fit the bigger id on the flywheel mount on the 350( 2 inch to 2 1/2 inch, im checking online and the part numbers are different for the years thanks

I didn't realize the two cranks were different sizes. Rats!

LockDoc

[geezer#99]

Originally Posted by LockDoc

I didn't realize the two cranks were different sizes. Rats!

LockDoc

The difference in the hub bore is due to a one piece or two piece rear main seal.

[LockDoc]

Originally Posted by geezer#99

The difference in the hub bore is due to a one piece or two piece rear main seal.

OK, thanks Geezer. I guess the year on the 305 wasn't posted.

LockDoc

[kx57]

I have been working on putting my SM465 transmission that was bolted onto a mid-70's car 305 that was in my '72 chev truck onto my '89 350 engine.

So I'm into similar problems.

Here is what I've discovered.

1. "There are two different size manual trans flywheels, 153 tooth and 168 tooth. Do you know which one you have?"

Not entirely true. There is also a 158 tooth which people seem to think doesn't exist. Except it does..because my SM465/305 combo had it in there. (I counted repeatedly)

This is the flywheel from Jegs I bought to get rid of the 158 tooth:

http://www.jegs.com/webapp/wcs/store...rsistYmm=false

2. The shaft has different spline count depending on your vintage

https://www.novak-adapt.com/knowledg.../manual/sm465/

Some good info there....but take it with a grain of salt.

Mine was a 10 spine. Even though my truck is a '72 and not 4WD.

3. In my particular case the crankshaft had a different bolt pattern on it than the '87 and earlier ones. That also affected my flywheel selection. The Jegs flywheel listed above bolted right up with no issues.

4. I reused my clutch pressure plate and clutch disc. They fit to the Jegs flywheel with no issue. I remember the measuring being goofy on the clutch disc. I forget if mine was "11" but actually measured 10-1/4" or what it was...just remember laughing at it because it didn't make sense at the time.