I have an early 4 port 13b in my FB. The center or intermediate plate has a port for an egr valve. The block off plate and bolts are in the way of my sidedraft air cleaner.
can you install a freezeplug in this opening? Anyone know the diameter? Thought I would check here before taking it apart..

 

installing a sidedraft? make your own aluminun block off plate using the orig EGR gasket. the hole is pretty large so i plug is a no no.