another flathead clutch question

i did a search and could not find much info on this problem. i have an 8BA flathead, and what i was told is a 53 merc overdrive 3 speed. it has a 10 spline X 1" input shaft. whenever i do a search all i seem to find is a 1 1/16 input shaft or bigger. also, i have 3 different flywheels and 3 different pressure plates to choose from in my stash. 9.5, 10, and 11, which one do i want to use? the 11?

ok so now, lets say i use the 11" disc. i need to find one that has the 10 spline X 1" input shaft. i tried napa and they updated there system(downgraded if you ask me) and they no longer have that information available! i tried autozone also. both searched for merc and ford. both came up drawing blanks.

 

the worst part about it is i think i HAD a clutch disc but threw it away thinking "ah, ill just buy a new one".........

 

The '53 type Merc would have same spline as many '50's Fords.
You have 3 choices (Be SURE wheels are 8BA, not earlier!), unless engine is going in a dumptruck choose the 9 1/2 and order readily available '49 Ford standard disc and pressure plate (which would not go on a pre-51 merc).
I would say 10 but I believe finding the late type disc in that size is difficult.
If any difficultie, just go to Joblot Automotive and deal with people who know what you are talking about.

 

UPDATE: i was thinking and i thought i might have thrown the clutch disc in a box with some other stuff. so i checked and i did. SO, i have the disc and its a 9.5 inch. but its no where near trustworthy condition.

 

ok so dont use the bigger clutch, and get all the 9.5 parts together and use them, correct?

i notice that the pressure plate i have was a bit smaller but i think the clutch disc would still fit in between the assembly.

 

that would be by far the easiest pile of parts to collect, and entirely ok unless building something really heavy. The heavy pressure plate and stiff springs make the 11 a poor choice except for actual truck use, the 10 is fairly rare in the '49-53 configuration and would be troublesome to get together. Be sure what you have...pre-1949 stuff and 1949-early '51 Merc require completely different parts.

 

is there an easy way to tell the difference between the early 9 inch clutch setup and the later one? i also read something about "long" and "short" pressure plates?

 

Early is 9, late is 9 1/2
any '32-48, '49--about '52 truck, or '49-very early '51 Merc is early, '49-up Ford and '51-up Merc is late.
The early uses a much bigger throwout and has shorter fingers on PP to fit. The disc will have a substantially bigger spline than late.
Look at you 11...if it is Ford, it should be early type, likewise the 9 1/2 would be late only. Wrong parts entirely incompatible.
Flywheels differ between ALL 8BA type applications and all '48 and back.