1976 d100 3 speed manual. looking at buying a clutch set/kit. am seeing 2 that say exact fit. one is a Diaphragm type clutch cover the other says Lever type clutch cover. when I replaced my throw out I saw that my truck has the diaphram type but I can I use either? also think one is 10inch while other is 11?

If you have the high mount starter you are limited to the 9 1/4" and 10" lever clutch style cover...if you have the "low mount" starter then you can get an 11" clutch with the diaphragm style cover....

You will need to note which clutch actuator you have, since the lever activated clutch like the the Borg and Beck 9 1/4" and 10" use the mechanically assisted linkage with the clutch pedal overcenter spring to assist in actuating the clutch.... on a diaphragm clutch you will have to remove that spring or the spring may leave the clutch pedal on the floor until it's pryed up...if your truck has the hydraulic slave clutch, or an after market hydraulic actuator, or your over center spring has already been removed then the diaphragm clutch is fine to install.

If this is just a stock style of clutch, 11" low mount starter, Luk makes a good stocker diaphragm replacement clutch for a reasonable price...I have one that I am installing as part of my Duster Clutch upgrade and hope the added surface facing will help my car from killing the smaller clutches during drag races....

Good luck!

thanks for the reply.mine is low starter no mechanical assist or anything

Are you refering to the pressure plate? The diaphram style pressure plate will have many "fingers" where the throwout bearing hits. like this one.
http://www.rockauto.com/en/moreinfo.php ... 36&jsn=423
While a non diaphram style will look like this.
http://www.rockauto.com/en/moreinfo.php ... 36&jsn=424
If i remember right the only difference is that the diaphram style is easier to operate witch is helpful if you dont have a hydraulic clutch. (and most dodge truck prior to the 80s dont). You can get both types in the 11" or the 10". But what DusterIdiot said is correct as well.

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~Nic

Actually both units are easy to operate if the cover is engineered correctly, the B&B and Long style of clutch have a set of weights on the levers in the cover that if the crankshaft is turning, will help make the clutch actuation easier (more so on the Long style of clutch that Ford and other brands have used because they have longer levers typically...) The diaphragm clutch can be just as hard to actuate if the diaphragm and springs aren't matched right, and some people do ask for heavier springs to make sure the ring clamps the disc during heavy abuse...

My favorite story is local racer Dave Mueller got a high end diaphragm clutch for his car, and the factory put the wrong springs in the the cover...after trying to get it to actuate with a 10' length of pipe over the fork and it wouldn't budge, he pulled the cover, called the factory, and the factory asked for the color of the paint on the springs....factory went whoops, you got too many of the wrong color in there....no wonder it won't actuate....

With diaphragm clutches, you also have to worry about making sure your linkage is set correctly, if you over actuate the clutch you can damage the 'fingers' so they are no longer all even, or in a real bad case you can unspring the diaphragm.

Actually a fair amount of base 3 spd and NP granny 4 speed trucks got the hydraulic slave clutch set up in the 60's, it went mostly to linkage when the bellhousing and flywheel got redesigned in the 70's, I have seen a few 80's trucks get the hydraulic set up (mostly HD packages like the D-150's).

I have seen the B&B in 9 1/4" and 10" standard... I have seen 10" offered in the diaphragm only to open the box and the cover is a B&B... (Zoom Clutch has done this...) Spec clutch used to offer the 10" in diaphragm clutches with everything from sprung hub kevlar pucks to solid hub iron facings... I have bought 3 of these and killed each one after a handful of launches (I got more launches out of my old stock B&B 9 1/4" from Zoom...).

You can get both in 10 1/2" (but those only fit small blocks...and you can't get that to fit without some adapters)....

You can get both in 11" (since this is the same size as most of mopar's big blocks), and in the diaphragm clutches you have options from stock organic facings on the disc to ceramic and sintered iron materials (got $600 for a clutch and not going to street drive it, right?)...

Since we are going through some of this information, there are a few things to note about mainshaft splines when picking the disc...

In the early-60's the trucks with some 3 speeds, and the NP-235/435 had a 10 spline disc... that's a tough one to get.
Later mopar moved on to the most common 1" diameter 23 spline discs that you find in most cars and trucks we work on with the common transmissions for 3 speeds, NP235/435, A-833 four speed, and it's variant the A-833OD.

If picking a performance clutch out be aware that the A-833 4 speed box in the late 60's/very early 70's and was beefed up to what is called the "hemi box", and was found behind the hemi and 440 six pack cars, this has a 1" shaft with 18 splines and will not work with your 1"x23 transmission mainshaft.

With "stock" brands for stock and mild engine builds I have had good luck with both Zoom and Luk brands, NAPA also has been OK, but it seems that some years you can get the disc and cover together, and a few years back they didn't have covers but you could buy just the disc...

Cheers!

I got a NP435 that is a 10 spline and I always wondered what it came in. I figured it was a military option.

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~Nic

thanks for replies all. more questions to come as soon as I post this one.