[Fot] TR6 backing plate question

[Walter Hollowell]

 I noticed that in my pile of backing plates that bolt on the the rear of
the block on my TR6 engines that some plates are thicker than others. Some
are aprox 3/16 and others are about a full 1/4" thick. Can anyone let me
know what this is all about and if it makes a difference as to which one I
use for the race engine I am building. I am using a late model block and
crank with a late model 4 speed bolted to it.
Thank You
Walt Hollowell
Abq., NM