What diameter clutch?
 

My clutch on my '70 is slipping (250/3 speed). All the part houses list a 10" and an 11". Which do I need and how would I check to see what's in there now? Need to get one ordered soon.

Re: What diameter clutch?
 

The only sure way to know, is to pull it out and measure the disc. From what I recall, most the trucks used the larger clutch. I'll say i've never seen the smaller in a truck.

Re: What diameter clutch?
 

Not exactly what I wanted to hear but definitely more info than I had, thanks. Unless someone else has a different opinion I'll order the 11" and roll the dice that it's the one I need. Thanks

Re: What diameter clutch?
 

Fwiw my 67 has an 11" clutch with a 250 and a 3 speed.

Re: What diameter clutch?
 

11" clutch, BB are 12, & 13".
IMHO......Aways resurface the flywheel, and pressure plate whenever changing the clutch. Like a new relationship, everything will mate up and get along much better when you complete those steps. Make sure to use the spline that should come w/ the new clutch so the disc and pressure plate are aligned correctly. If the trans will not slide in relatively easy, DO NOT force it, and NEVER EVER draw it to the bell housing with the bolts. If you have to do that, someting's wrong. Lastly, don't ask me how I know.

Re: What diameter clutch?
 

Great info. Preciate it guys, I ordered a new 11" clutch set and flywheel. Figured it be the safest bet.

Re: What diameter clutch?
 

As long as you have it out it wouldn't hurt to change the input shaft pilot bushing in the end of the crank. theyr'e cheap and easy to remove. fill it with grease and find a dowel the size of the hole and hit it with a hammer. it will come out.

Re: What diameter clutch?
 

The set comes with the clutch, pressure plate, throw out bearing and pilot bearing I believe.

Re: What diameter clutch?
 

If you currently have a 10" clutch, then you can only replace with a 10" due to the flywheel bolt circle. If you have an 11", then you can put an 11" or a 12".

The two ways to know whats in there is if you have something like HD Clutch on your spid, then you have an 11".

Be sure to get your flywheel reground.

Re: What diameter clutch?
 

Thanks. Nothing like that on the SPID, mine is almost blank lol. I ordered a new flywheel too.