250L6 to 71 350 - Can I use the 250L6 Pressure plate setup on the 350?

[Yamariv]

Hey gents!

Bringing in my 71 350 out of a Biscayne which had an automatic to the machine shop tomorrow. Was wondering what I need to get to convert the 350 to mate to my 3 Speed Saginaw.. Can I use the 250's pressure plate setup or would that be too small?

[Yamariv]

Anyone?

[Wrenchbender Ret]

It really depends on what kind of use you have in mind & the size of the clutch that is in it. If it is an 11 in. clutch you are ok. If it is a 10 in. it will work if you are not going to do some heavy pulling. The flywheel will fit also.
A smaller clutch makes shifting easier & is better for the syncros in the trans.

George

[oneshotkyle]

10” have there own specific flywheel, 11” have there own specific flywheel also. I had taken out my 11” and tried using a sbc standard one which is 12” and to large for my inline 6 flywheel. Went back to orielly and they got a 10” the next day. The 10” pressure plate was to small to bolt up. Had to use a 11” so another day went by and the 11” worked out. Sbc and inline 6 are both internally balanced and can interchange flywheels.

[Yamariv]

Originally Posted by oneshotkyle

10” have there own specific flywheel, 11” have there own specific flywheel also. I had taken out my 11” and tried using a sbc standard one which is 12” and to large for my inline 6 flywheel. Went back to orielly and they got a 10” the next day. The 10” pressure plate was to small to bolt up. Had to use a 11” so another day went by and the 11” worked out. Sbc and inline 6 are both internally balanced and can interchange flywheels.

Thanks guys, appreciate the info!

So rookie question..is there any chance to use the automatic tranny flywheel that's still on the SBC engine and just buy a pressure plate to bolt to that or do you always need a specific flywheel for a standard tranny and then buy the right pressure plate to match the flywheel?

So looks like I need an 11 inch pressure plate for sure, spending a lot on the SBC rebuild, definitely want to go with the right size pressure plate.

Are new pressure plates very expensive?

[oneshotkyle]

Originally Posted by Yamariv

Thanks guys, appreciate the info!

So rookie question..is there any chance to use the automatic tranny flywheel that's still on the SBC engine and just buy a pressure plate to bolt to that or do you always need a specific flywheel for a standard tranny and then buy the right pressure plate to match the flywheel?

So looks like I need an 11 inch pressure plate for sure, spending a lot on the SBC rebuild, definitely want to go with the right size pressure plate.

Are new pressure plates very expensive?

Automatic has a flexplate that bolts to converter
Manual is a heavy surfaceable flywheel

A brand new clutch/pressure plate/pilot bearing and installation tool come as a kit and would be less than 150.00

[Yamariv]

Originally Posted by oneshotkyle

Automatic has a flexplate that bolts to converter
Manual is a heavy surfaceable flywheel

A brand new clutch/pressure plate/pilot bearing and installation tool come as a kit and would be less than 150.00

Ahh ok, I'll just go aftermarket kit then cause I need a new clutch anyway

So last clarification, is the pressure plate in the kit the same piece as the flywheel for a standard? or do I need to buy a ring gear and attach it to the pressure plate?

[oneshotkyle]

Originally Posted by Yamariv

Ahh ok, I'll just go aftermarket kit then cause I need a new clutch anyway

So last clarification, is the pressure plate in the kit the same piece as the flywheel for a standard? or do I need to buy a ring gear and attach it to the pressure plate?

I think you need someone to do the work as you seem confused on what the parts are. Either way hope this helps

[Yamariv]

Originally Posted by oneshotkyle

I think you need someone to do the work as you seem confused on what the parts are. Either way hope this helps

Thanks for the diagram, what I was trying to clarify was if the pressure plate and flywheel for a standard transmission is one piece or is it two separate pieces that I have to bolt together.

From the pic it looks like one piece?

[Accelo]

Don't forget you will need to install a pilot bushing into the crankshaft.
All the crankshafts had the hole to install one but only the manual transmission vehicles had the pilot bearing/bushing installed.
Don't confuse what is sometimes called a "pilot bearing" with an actual roller bearing. They were sintered bronze bushings from the factory.
Lots of people interchange the two terms:
"pilot bearing" & "pilot bushing."

[Yamariv]

Originally Posted by Accelo

Don't forget you will need to install a pilot bushing into the crankshaft.
All the crankshafts had the hole to install one but only the manual transmission vehicles had the pilot bearing/bushing installed.
Don't confuse what is sometimes called a "pilot bearing" with an actual roller bearing. They were sintered bronze bushings from the factory.
Lots of people interchange the two terms:
"pilot bearing" & "pilot bushing."

Great point, thank you!

[LockDoc]

Originally Posted by Yamariv

Thanks for the diagram, what I was trying to clarify was if the pressure plate and flywheel for a standard transmission is one piece or is it two separate pieces that I have to bolt together.

From the pic it looks like one piece?

As shown in the diagram the flywheel and pressure plate are two separate pieces that have to be bolted together, with the clutch disk in between them..... The clutch disk has to go in a certain direction and it should be marked. "Flywheel Side"

[Yamariv]

Originally Posted by LockDoc

As shown in the diagram the flywheel and pressure plate are two separate pieces that have to be bolted together, with the clutch disk in between them..... The clutch disk has to go in a certain direction and it should be marked. "Flywheel Side"

Perfect, good to know!

[geezer#99]

Are you putting the motor and transmission togethor away from the truck and then install them or leaving the bellhousing and transmission in the truck and mating the motor to it?

[Yamariv]

Originally Posted by geezer#99

Are you putting the motor and transmission togethor away from the truck and then install them or leaving the bellhousing and transmission in the truck and mating the motor to it?

Going to pull and reinstall the motor and tranny together if I can. Do the clutch while it's out and easily accessible

[geezer#99]

Have you figured out your motor mount locations yet?

[Yamariv]

Originally Posted by geezer#99

Have you figured out your motor mount locations yet?

Still debating if I'm going to try and find the correct V8 cross member so the engine doesn't sit so far back when you convert from the L6. Does it not bolt right up if I stick it in the L6 location?

[geezer#99]

I’m not sure.
Someone else might chime in to answer that.