Does anyone think the front bass head needs to be changed after 40 years and does it make sense to go to a solid head?
If you're willing to try this, i would suggest the following.
In keeping with the "vistalite" classic rock 70's sound, i'd go with a
Remo Powerstroke 3 Black dot, and a clear Powerstroke 3 (the one without the 2 black rings). This is basically the same as having a clear Ambassador head with a felt strip, and a classic control sound CS black dot head with a felt strip. I personally use no porthole in my 22" kick and leave it wide open. It literally sounds as big as a 24"..John Bonham never had a porthole cut, and got a punchy, massive resonant sound while maintaining enough control without any unwanted overtones. I was a drum tech for a buddy of mine's Zeppelin tribute, and when he gave me the go-ahead (no pun ;)) to choose his drum heads and tune it the way i suggested, my buddy, his bandmates, and soundman, all loved the sound, saying it was true to the original "Bonham sound". The soundman was particularly baffled at how i got a controlled "thump" with no porthole in the resonant head.
Batter side tuned up to one full turn on all tension rods after finger tensioning, and the reso side tuned up slightly higher than that to control the airflow which can create unwanted overtones. The internal dampening rings on both heads should keep the drum in control, giving your bass drum the ultimate in power, bottom end, controlled resonance, and "thump" you're looking for.. Hope this helps you out ;)