LA top end rebuild question

I dunno... I have a Cloyes Double roller in mine... Over, 40,000 miles later, daily driven and many 1000+ mile trips after my rebuild. I still maintain timing and have no issues...
Now, with the money I saved I just went ahead and bought a set of ported big valve 340 J-heads for $200 from a local Mopar fanatic to replace my tired, worn 308 heads (over 250K miles on them).