How to properly adjust 66 289 mustang rockers

Verifying rocker adjustment to end a debate. One guy says to adjust on the tighter side, one guy says to go on the looser side. Let's see what works.

[@rabaham]

That is the best way to adjust the valves is to use the pressure guage to measure compression

[@robpeters5204]

He says 429 valve adjustment in the beginning. Does he not know his engines or what he is working on?

[@ashleymaharaj2192]

How are they setting rocker arms with no oil pressure in the lifters because I thought the distributor turned the oil pump as it's not in

[@themedic4050]

They are setting rocker contact end-play. The 3/4 turn is the only gap between the top lifter clip and the top of the upper lifter piston. Once the engine starts or they pump up the lifters by cycling the pump and engine, the lifter will pump up and take up the space to zero lash.