HELP, sb magnum 360 pushrods

my frend have stroked 360 , 408, old block 1975.

now installing magnum rt steelheads, and have hyd.roller cam.

we have here 7.200 " long pushrods, but these are too long !

maybe it have to be 7.000" ??????????????

what is right lenght ???????????

Thanks

6.91 is the length of the factory magnum pushrod.
But I would get a length checker before I guessed.
Lifter height and type will change this requirement.