fuel return line?

[surfersmurf]

i have a 79 trans am 400 4 speed. and i just ordered a rebuild kit and some other parts for my quadrajet from cliff. i also ordered a new mechanical fuel pump from summit. my question is do i need the fuel return line. the previous owner of my car never had one and just had the return blocked off at the pump. i have read quite a few threads in other places debating this and it seems to be 50/50 on the answer. my car has a

400 .030 over
comp cam 280H
pontiac 670 heads
4 speed

the car does not have the charcoal canister or the vent from it to the tank either. it appears that the previous owner mad a vent from the top of the tank uring the return inlet.

[Schurkey]

The fuel return on an OEM fuel pump is more of a vapor return.  Does no harm, does some good especially in hot weather.

My Father-In-Law's '77 Trans Am was similarly butchered at the fuel pump; we reinstalled the proper fuel return when the engine was replaced.

[surfersmurf]

thats cool, ill block the return for now and make plans to drop the tank and hook up the return. i have a few other issues to address that are on the front burner. thanks for the reply.

[73ss]

If you block off the return line coming from an OE style pump, Pressure will climb to 9~10 PSI. This will cause all kinds of problems. I learned this first hand. If your running an aftermarket pump with no return port, It should be fine if pressure doesn't go above 6. Will probably cause you some grief in hot weather. Doen't seem to take much to boil gas nowadays..