block plate-needed with a stick car?

i am getting a mustang running for someone that has a 351w and a t-5 in it.the last mechanic that put the motor and trans in the car didnt put in the plate that goes between the motor and trans.it seems to start fine,but i havent driven it yet.this car will only be driven about once a week and track duty.is the block plate really needed?
 
I don't believe it's absolutely necessary. My understanding was that it kept the clutch material off the back of the block, and helped locate the starter with the bellhousing. I'm sure it served more purpose than that, but I don't see it as being for safety or anything. If you're working fine without it, I'd think you're ok?
 
The block plate also serves to cover the lower front section of the flywheel & bellhousing so that it isn't exposed to the open street. No cover means that if you run over something, it could get caught up inside the bellhousing & between the flywheel & bellhousing. Think of what damage a big rock could do...