pfergy600

I have 72 Cutlass 2dr Hardtop Coupe, with a base model 350 2bbl Carb.
(WITH AC) I am in the process of putting a 455 Big Block (from a 1971 - 442). The fuel pump I have now only has one fuel outlet and the send unit one also. I read somewhere that the 71 big block 455 with AC has Two (2) Outlets (one fuel & the other a return) on the fuel pump & fuel tank sending unit. I guess my question is can I use my existing fuel pump & sending unit or do I need to buy the ones with Two Outlets? I did buy a new 20 gal. Fuel Tank with 3 Vents. Thanks in advance for any feed back. Kind of new to this site..

PS - Not sure if it matters, but the 72 model has a Fuel Standpipe Assembly mounted behind the backseat and the 71 model did not I believe.

rjohnson442

Yes the 455 cars with ac have a return line on the fuel pump. You can run with the one you have though no problems, if you don't want to get a new pump.

pfergy600

Will it affect the fuel pressure (more or less) going to the engine? Thanks for your reply.

joe_padavano

The second line is for fuel return, which helps prevent fuel percolation by recirculating hot underhood fuel back to the tank. It's nice to have, especially with today's ethanol-loaded gas, but not mandatory.

DeltaCustom'69

my '69 delta has the base 455 but, has edelbrock intake, demon carb, but the fuel pump has 3 outlets. Supply. Return, and One that runs to the carb. Ive had a hell of a time for two weeks now finding a pump that fit. Once I got one that was close, I I had to go to Lowes for some copper fittings/elbows and whatnot to get the pump to fit without kinking the lines. ( they were running directly into the frame) I still am not getting fuel from the tank to the pump though

rjohnson442

Any stock pump will fit a stock motor? do you have a pick of the way you have it set up now? the factory used rubber lines from the frame to the pump. You can test the pump with some hose and a gas can. plug the return line, attach hose to in line and put in a can of gas. attach piece hose to carb side of pump and crank it. if it's not sucking and pumping you probably installed the pump on the wrong side of the pump cam.it should look like this installed.
if you open the gas cap and blow through the line from the front rail back you should hear the air in the tank if not you probably have a pinched line. If you hear air anywhere along the rail you have a hole in the line.
lol gas in the car? sometimes we have to start simple around here.

DeltaCustom'69

For those like me, this will make you feel a little stupid, but on the 2nd gen 455s the fuel pump is inverted. It doesn't bolt on like a small blk chev...>>Brain Fart! i stumbled on a pic of a guys BOAT! engine and noticed that.