72 Suburban Build

[geemac]

72 Burb with a transplanted Cadillac 500/THM 400. Had some fuel starving problems this summer...new mechanical pump, dropped and cleaned the tank, blew out the lines and replaced the pickup/sending unit.

The 40 year old sending unit has a supply and return line from the original 350/THM 350. I could only find a single pickup tube replacement, but the tank has 2 other 3/8 hose barbs in what appears to be a vent system. Wonder if I can use these for the return line? (Caddy 500 pump needs a return line).

Anyone seen anything like this? How about a service manual diagram for the fuel line system? Different for the C10 72 Burb vs a truck?

Thanks in advance if someone can help! Glenn (geemac)