481x piston to head clearance

Hello

I am currently helping a friend service a recently purchased zero run 540inch 481x. The issue I have is the piston to head clearance, the pistons currently sit at zero deck with a 60th head gasket, giving only 60th piston to head clearance(flat top piston with valve relief). i have built a few hemis with lots more clearance. Was wondering how much you normally run as a minimum on these motors.

Thankyou

clarky

 

The standard deal on the 481 is .025 down and thinnest head gasket they recommend is a .050
I always run more though