Easy Fuel pump question...Help Guys!
 

I am replacing a stock 72' 350 4-barrel and it has two lines going into the bottom of the fuel pump. The motor I am replacing it with is a 72' also , a 307 2-barrel and it has one line feeding it with fuel.

What the hell do I do with the second line and what is it their for?

I need help guys!!

ttt---help!
 

ttt---help!

Guys!! I really need to know what's up!! Please let me know
'
Thanks

One is a return line. Just plug the return line and run it.

the fuel pump should have 2 places to connect lines.......1 line goes to the gas tank [inlet] and the 2nd line [outlet] goes to the carb,,,,,,,,,

Mine has three total...two on bottom and one going to the carb. WHich one do I plug if one of them is the return line?

Thanks guys

Jeff

Just run the fuel pump for the 350 on the 307...it should bolt right up. It has been awhile since i have replaced a fuel pump, but i am pretty sure all of the lines have different sized fittings so you can't mess them up. If you want to use the 307 pump, the smaller line going back towards the tank is the return line, plug it.

oops...i re-read your post, you are hooking it up to a 2bbl carb....i believe that is what determines the difference in the fuel pump, the 4bbl pump has a return line, and the 2-bbl dosen't. In that case, just plug the smaller return line....OR

Put your 4bbl intanke and carb on the 307 and run the 350 fuel pump. Gotta have a 4bbl :)

Just checked - my OEM Q-jet 350 has 2 lines... :)

If it's a 72 307 don't try that 4 bbl without the 350 heads as well. the 72 307 has tiny little ports and won't be the effort of a 4 bbl swap without better heads.

When mine was a OEM Q-jet 350, TH350 truck, it had 3 lines, one going to the carb, and two going from the tank to the pump :)

Thanks alot guys!
 

I think I'll just swap the fuel pumps and save myself from having to think too much!

Really, thanks for all the info

Jeff

Oh yeah, I forgot to mention that the bottom of the pump is market inlet outlet, and return.

The return line was there to circulate fuel around the inside of the pump.This was to keep the pump cooler to prevent vapor lock.

You can swap pumps but you may find the outlet from the pump to the 2 bl carb on the 307 takes a 5/16" fuel line and the 350 with the 4 bl takes a 3/8" line. So you will have to fab the two together.

I just had that problem myself, had bad problems with vapor lock until I put the two line pump back on. No problems now.

Thanks guys!
 

I am going to try the stock 307 pump first and then switch if I have trouble. Thanks for all the information!

Jeff