A piece of angle iron about a foot long or so, drill a couple holes in it so you can bolt it to the exhaust side of the head………works great as a place to mount the mag base for the dial indicator…….for checking actual valve lift.
Do you know the history of the heads?
Bought new, fairly recently as assemblies…..or bare heads?
The reason I ask is, when those first came out……some places sold them with long BBC valves in them, which were .250” or so too long.
The correct length is:
5.350” intake
5.375” exhaust
Some related reading:
Some Pro Comp "Victor" stuff.....
