Yes, with those heads on that many cubes, there is still a huge amount of untapped power with cam/compression/intake changes. That particular combination is probably super reliable and low maintenance. It's amazing the cylinder head
development still taking place for the SBC. It goes in every direction too. There is stuff like these 15 degree heads and other 9 and 18 degree development, and at the same time there are guys like Chad Speier who have expanded the lungs of 23 degree stuff like crazy.