#1
I have a Fender Custom Vibrolux which has the crappiest Reverb sound ever. I tried swapping the reverb tank with the one in my Fender Eighty-Five, but when I plugged it in, I got absolutely no reverb. Am I missing something? Is it a problem between solid state and tube?
Try adding more delay.
#2
So you need to check the ohms and circuit type. Reverb tanks all have different grounding schemes and circuit requirements.
Prs se Holcomb is the answer
#3
Yes, reverb tanks have 'specs' and amps have 'requirements' for types of reverb tanks. You usually can't just switch one for the other. 
Dave @ Seymour Duncan