need clutch help

[General Mayhem]

hey guys i need some help, i'm converting my blazer to a sm465, so i went out and bought a new flywheel from a local parts store, and now i don't know what size clutch will fit on it, i'm hopeing a 12inch but im not sure if it is only for an 11inch, so i got some mesurements here for u guys and i hope u can tell me what i need

overall size to outside of teeth is about 14 1/8, has 168 teeth
flat face were clutch and presure plate go is about 13 1/4
presure plate mounts holes are about 12 5/8

Thanks guys

 

[gnihcraes]

my 1 ton with sm465 takes this and they should be the same...

# Clutch Disc Splines : 10
Clutch Cover Type : Raised Diaphragm
Cover Size : 12"
Disc Hub I.D./Input Shaft Size : 1 1/8"
Disc Material Type : Organic

1985 GMC Truck K3500 1 Ton 4WD - Pickup
Engines : 5.7 L 350 CID V8
Comments: Disc Size: 12"-10-1 1/8";w/ Raised Diaphragm;w/ Flat Flywheel

hope this helps some...

 

[GMC Truck]

hey guys i need some help, i'm converting my blazer to a sm465, so i went out and bought a new flywheel from a local parts store, and now i don't know what size clutch will fit on it, i'm hopeing a 12inch but im not sure if it is only for an 11inch, so i got some mesurements here for u guys and i hope u can tell me what i need

overall size to outside of teeth is about 14 1/8, has 168 teeth
flat face were clutch and presure plate go is about 13 1/4
presure plate mounts holes are about 12 5/8

Thanks guys

Yep a 12 inch will fit a 14 inch flywheel. I run a 12 inch Borg&Beck style in my truck, I just like em better than the diaphragm type.

 

[diesel4me]

I had 3 of those 3 fingered pressure plates fail rapidly in my '72 K5--I replaced the 12" one with an 11" diaphram type and it was MUCH better as far as pedal effory and had no issues with the clutch thereafter..it may have just been crappy Borg Warner rebuilts,but I sold many of the 12" B&B clutches at the parts stores,and I was not the only one who had bad luck with them..

There is about the same surface area in an 11" as a 12"--one drag racer I know swears by using the 10.5" clutches ,he claims they are lighter and have more friction surface than the larger ones..I always thought bigger was better,thats whgy I used a 12",but I wouldn't use a 3 fingered PP again..maybe a diaphram one..

 

[GMC Truck]

What failed on yours? I have had good luck with mine but I dont buy cheap clutches, too much to lose if it fails bad! The 11 inch diaphragm clutch is a good unit too but heat really messes with the springs in them. Not a good choice if you need to "slip" it a little now and then.... but thats just my 2 cents.

 

[diesel4me]

All of the 12" 3 fingered pressure plates had one "finger" either snap off or go way out of adjustment,and then the clutch wouldn't release fully at first,then not at all...one broke at a red light while I was holding the clutch in,in first gear,and the truck lurched forward,and bumped a nice shiny red vette with a HUGE black guy driving it,I thought I was a dead man!.but he shrugged it off when he saw no damage,thank GOD..

I put an 11" centerforce diaphram style pressure plate & disc in it after the third 3 fingered 12" one failed--I got it used at a swap meet with about 100 miles on it,from a guy who's wife couldn't drive a standard in his Chevelle,so he swapped a TH400 in it instead..got the whole setup for 50 bucks!...I never plowed or off roaded my 72 K5,but it did get driven a lot of miles in city & highway traffic,never had any clutch troubles..I think those 12" pressure plates fubared my left hip and leg,I get real bad pains in it often now that I'm over 50!..

 

[GMC Truck]

Man that sucks on the vette thing! Your right on the clutch thing though, for a daily driver on the street the regular clutch is a leg saver. Thats why GM went hydraulic in the later years.