Mercarb 2BBL vacuum hose?

[Scott06]

Scott06: that is a set screw that is in place and not installed by me. this is a different engine from original. Based on the casting number of the block its a 1988-1994 SBC and the boat is a 1998. I'm also assuming that the carb is from the original 1998 5.7 which probably had an electric fuel pump and the reason for the setscrew in place of the diaphragm nipple.

Yes makes sense. So put a nipple where the pipe plug is and put the Tyson tube up from mechanical fuel pump.

interestingly while new build engines (except 3.0) used electric pumps from mid 90s on, the merc reman 357 alpha/ bravo engines they use a simple mechanical pump , assume they machine the block for the fuel pump pushrod.

 

[flashback]

The fuel pump needs to be vented to the carb unless it has a bowl that can collect leaking fuel.