Mike, although the 12" will give exceptional clamping force, it will rob HP to turn that extra mass. beyond 11" probably isn't necessary unless you are driving a big rig. Yes have it balanced with pressure plate.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

For the record......



The 12" clutch and pressure plate Physically fit and will rotate without ANY interference with the bell-housing, dust shield, starter, throwout arm, throwout bearing, input shaft etc. The throwout bearing and pilot bushing included in the kit visually appear and fit like the ones that were removed. With this installed, the throw out arm is straight, or perpendicular to the center-line of the engine. The only issue that i can foresee is possible adjustment of the throw out arm/linkage. However that being said there appears to be more than enough adjustment on the linkage.



Remember this was tested with a truck bell-housing and the light duty 3 speed transmission from a stock 61 F100. Obviously the flywheel will have to be re-drilled to mount the larger pressure plate. My engine shop recommended re-balancing the flywheel with the pressure plate mounted to alleviate any balance issues.

I pulled my bell-housing off to clean it up before going back into the truck......It has the casting #TAAM 7505-B. My machinist said that he would re-drill my flywheel for $40, so i said go ahead and we will try this experiment, and see if there is any interference.

I have a 10 1/2" assembly that I removed from an engine out of a '56 F100 with three speed tranny. I never drove the truck as I bought the engine when the guy went darkside on his truck. The clutch has obviously been replaced and the wear lining surfaces of the disk have not fully worn in yet. Springs and spacers all seem tight. Throwout bearing included is tight and smooth. Spline for the main drive is 1 3/8" If you're interested I can send pictures. $50. plus shipping from 37874

ray

FWIW,,,the bellhousing in my F600 with a 12' clutch has cast # of TEAL 7505B, it has a bolt pattern for a Clark 5 speed.

My '54 f100 has the 1 3/8" 10 spline light duty trans. It had a 10" clutch, I went to 11" thanks to Kevin.

  Dennis in Lititz PA

Charlie you are correct in that they did make large 1.375 x 10 spline for some light duty's, now that I think of it my 58 truck had the big spline with the small diameter clutch, that was an oddity I came across.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

I just went to check my sanity and my 3 speed is definitely 1 3/8-10 spline. I bought 2 clutches for the same application, '61 F100, 292, 3spd and both clutches fit that transmission, both are 11" - I still have those, too. Spline size wasn't an option when I ordered. And all of the clutches which were suppose to be correct according to the application but weren't did have 1 3/8-10 spline.

I also saw that the transmission has C3... part numbers on the case, front bearing retainer, and tailshaft housing so it is not a '61 transmission.

I have a 4 speed I pulled from a '58 or so F350 which also has a 1 3/8 10 spline. I also have another truck 3speed but it's still mounted to an engine but the case is entirely different from the other and there's too much crud to read the numbers.

According to my '61 shop manual, an F100 or F250 with the 8-cylinder engine has a 10.5" clutch. An F100 or F250 with the 4speed (optional for a 223 6-cylinder) or 4-wheel drive had the 11" clutch. 350 and bigger trucks have 11", 11.5" or 12" - I won't outline it all here. The spline dimensions are not indicated.

Since my transmission is not from '61, I don't think I can guarantee that it is 1 3/8-10. But I had not heard that there are other sizes until today. Considering that I ordered 2 clutches almost 8 years apart for the same application which each produced the same dimension product, I would almost be willing to put money on it that 1 3/8-10 is correct.

You know what, I'm going to ask Numberdummy over on fte. - His books don't indicate the size.

Napa online list the same 12" clutch for my truck and it is incorrect.


Lawrenceville, GA

The heavy duty trucks used the 1 3/8" x 10 spline normally in 11 & 12 " dia, the lighter duty used 1 1/16" X 10 spline in 10 & 10.5". The only place to get them is through NAPA. I went through this recently trying to get one from Autowise, they called the distributor because they had one listed and the distributor told them they could not sell them that size clutch I would have to get it through NAPA. Evidently NAPA has a contract with the distributor which only allows them to offer that size clutch.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

MetalMike: If you live in or near a reasonably large metropolitan area, you should be able to have your parts rebuilt.   Typically these are heavy duty truck shops.  They can reline your disc and the pressure plate can be refreshed as needed.  Have the flywheel resurfaced too.  Use new high strength fasteners and a new throw-out bearing.  Don't forget the pilot bushing in the back of the crank while you are at it.  This should give you many miles of satisfactory service.  Finally, IMO, you may want to seek another parts store.