Whats this ?

[mustangmike6996]

this may be a dumb question. how does one check the main bearing clearance?

Id assume thru the bore with no pistons installed or paltigage

 

[OldbutNew]

Nice piece!! Definitely LS7R out of one of the Caddy's or one of those yellow Corvettes. That baby might have done the 24 Huers du Mans.
Check the main bores through the rear main. Dial bore gauge or CMM.
Becker casting and Schwartz machined. THAT is a bad bitch!!