318 LA rebuild after losing a valve seat

Where did you get these tork to yield fasteners
never seen them for a SBM
mfg and part number please
if you use 71 vintage rods- whatever they were heavy or light- someone can post where the break was
and your pistons and pins are close to stock weight you are good to go
IF
you did change rods from 71 then weigh the big end and the small end and weigh the pistons old and new and let's see where we're at using the weight of the big end plus half the weight of the small end plus piston formula
and compare
maybe you get luck with a heavier rod but lighter piston (and pin) :)