Replumbing a late 70's jet with stock BBC, thru transom logs/snails, Dominator pump. Looks like the T takes 3/4" water hose in (hose barb fitting) and out to 5/8" (hose barb).

Should I use 3/4" hose from pump to T then 5/8" on either side of the T to logs, block and snails?

Regarding the gate valve, all that I've found are NPT.

Should I use NPT to hose barb fittings and clamps?

Exhause hose: My snails and tips are 2 7/8" OD however, the snails have a lip all the way around the exhaust end and the ball park measurement looks like the lip gives me approximately 3" OD there.

Should I go with 2 7/8" ID hose and muscle it on or go with 3" ID and clamp the crap out of them on both ends?

Advice appreciated;

Jamie Wexler
Kentucky