I'm putting one in. My 539 want to use crower solid rollers what spring pressure should seat and open and lash is reccommended don't want to use expensive hydraulic lifters I have these with no hrs

Have you got aluminum heads?

You have to account for the hot engine dimensions. Going solid on a hyd cam can have mixed results depening on hyd roller lobe design.

Lash ramps on solid cams are designed to take up the slack and get the lifter moving. Despite being a range of lash, there is an optimal lash. If too loose...the lifter misses some of the accelerating ramp and it hammers it hard.

You're prabably going to have to set it up and run it...test and adjust. Between 0.001-0.004" lash hot. You want a clearance lash for both hot and cold. You don't want to start hammering your rollers with the hyd lobe. Milder hyd rollers will be easier on the lifters vs a high intensity hyd lobe.

You don't have a lot of tolerance for setting lash...about a 2-3 thou window or less.

Why don't you re-grind the 741 or get a solid roller made up?