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.
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
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