Identifying INDY rocker arm ratio?

Were trying to order some T&D rockers after busting an INDY rocker but unsure of the ratio. Is there an easy way of finding out? We dont have much info on this motor. The heads are 440-EZ 295'S and have black INDY rockers on them.

black 1.5 blue 1.6... some will verify this im sure though....

If you knw the cam lobe lift you can set the lash at zero and open the valve all the way by turning the cranksahft with a dial indicator on the retainer(make sure the dial indicator stem is on the same angle as the valve stem from left to right and front to back)and take the net valve lift and do the math. IE .400 lobe lift times 1.5 = .600, 1.6 times .400 = .640. Don't be suprised if the ratio are off some

Sledgehammer is correct. Indy Blacks are 1.5.