Im looking to do the Holley Sniper conversion on my Merc 502's. The guy on the Holley tech line recommended using their in-tank fuel pumps which won't require a return line:
https://www.holley.com/products/fuel...e/parts/19-360
He says just drain the tanks, cut a hole in the top and drop them in, they self clamp to seal shut. They work for tanks up to 12 inches deep or you can fab an extension and splice in some additional wiring to go deeper.
Anybody know the depth on the cafe tanks, or other suggestions? Not running a return line sounds nice, though im less keen about draining and drilling the tank.

If you don't find an answer here, call Dustin @ Carters power boats probably no one knows the Cafe better than he

Thanks, I may do that.
I did notice you were one of the few who said its possible to run a return line to the filter head, which would be easier than back to the tank. Keeping that in mind as an option.

Thats the way Whipples instructions are on my kits, its a Teague filter head -10 in and out with a -6 off the back side of the regulator

My filter head has a return port so I could probably use what ive got.
Regarding the in tank pump, it just struck me that this may be problematic if the fuel filter isnt built for high pressure. In my old motors I was running an electric fuel pump but they were on the motor so after the fuel filter.
Is the pump before the filter on your setup?

mine is -10 from the tank to a 100 micro filter coupled to the A1000 aeromotive pump then to the filter head...........I agree I dont think Id want the pump in the tank

I got a new pick up tube for my friend's 36 Apache. It was about 21" deep.

safest way to know exact depth of any tank is to pull the sender or pick-up tube and measure to the btm.....factory original, aftermarket replacement or even setting a replacement tank in the carcass of the original - only way to be sure is to measure.

I have the floor out of my Cafe but even then there is no accurate way to tell the tank depth. As others have said would need to remove the pickup & go inside.
My return lines are ran back to my filter head, but the filter & pump are mounted on the bulkhead.