Crank Shafts and Clutches
 

Question:

So is the flywheel forward portion of a "Pilot Shaft" style crank the same for both small blocks and big blocks?

I am trying to figure out what clutches, bells, etc. I can use on a OS 18TZ with a pilot shaft crank. There are far more available in the 1/8th market, but I can't tell how they are actually different in any way?

Please shed the light on this for me.

Thanks much,
Spiro