[Amps] Mod thunderbolt to 4CX800A

[Bob Good]

I would appreciate comments on the feasibility of modifying an old Johnson Thunderbolt Amp (4-400A's , tuned /  swamped input) to use 4CX800A's.  In doing so, I would also desire to include 160 meters.  Care nothing about useage above 20 meters.  I would expect to add fixed inductance to the roller inductor, change or add to the plate RFC, add caps to plate tuning  and loading, modify input bandswitching for 160 meters, adjust screen / grid parameters.  Will use only on 230vac. Continue to use tuned input.   Questions:  
Does the P/S have enough plate current capacity?  Is the cooling adaquate?  How about including most desirable QSK from available kits?  I've also seen kits for inrush and grid protection, etc.  Exciter will be Omni VI.  Thanks to Amps for posting and to all who reply.   Regards,  Bob K4BG