Do these pumps require a gear-drive on the cam or is a timing chain sufficient? Also, what do most people do on the GenV carbed engines for fuel pumps when the cam-drive seawater pump takes the place of the stock seawater/fuel pump setup?

I had a set of cam driven pumps on my 454's. Timing chains, worked well no problems, the alum. timing covers went bad. Still have the cam pumps in the garage.