I had an lg4 that is currently being replaced w/ a 350. The fuel pump that was on the lg4 had 2 lines to it, but the one on the 350 only had one. What is the deal with this? I am still plaing on running the cc carb setup. I was wondering does the computer controlled carb require the second one or should I use the other style. Also, what is a good aftermarket pump that would be compatable with whatever I need to use. By the way It has ported heads, approx 10:1 compression, xe 268 comp cam, hooker lt headers ported intake, and new metering rods and hanger in carb.

Thanks

Ben

 

The stock pump on your LG4 had two lines..one feed line and one return line.The pump on the 350 has only a feed line.I would say for your application to get a new pump for a LG4 and put it on the 350 so you can keep all your emissions devices working properly.Your cc carb requires(as far as I know)this second return line and I myself do not know of any aftermarket suppliers making a mechanical pump that has a feed and a return line like the stock LG4 pump,leaving you to purchase a stock replacement from your local parts store.Look here https://www.thirdgen.org/newdesign/a.../rebirth.shtml ..it is a magazine article that can be found in the "Magazine Articles" section on our main page,there is a part two to this one that gives plenty of info on your type pf situation.Hope this helps ya out

 

I am removing the air pump and all associated hoses already, so I am not woried about emissions equiptment. Does anyone know if this is required and also if it will be able to fuel my 350?

Ben

 

I will read the article when I go home. I will see if it helps but other opinions are welcome also.

Ben

 

'Momar' what ever you do make sure you plug the return line if your not going to use, or you'll unload a few gallons of gas everywhere if your don't.

Ron

 

Well, wouldnt that be fun. Maybe I could blow myself up. So does anyone know if I would need it with the computer controlled carb?

Thanks

Ben

 

It doesn't really have anything to do with the CC carb specifically. It is a simple return line that sends the excess capacity back to the tank. The idea is that if the fuel is constantly circulated, it is less likely to pick up heat in stop & go situations. It's supposed to be for vapor lock mitagation, that's all, which doesn't have anything to do with CC or non-CC.

I've got an AC replacement pump on mine, which has fed it successfully to 6300 RPMs with no indication of fuel starvation whatsoever. I doubt your 350 would require significantly more than mine does.

 

Well, thats good to know. What are the specs of your cam.

Ben

 

If you want to see over kill.

I'm running a Holley VolumeMax. It puts out 170gph, has a #10 input & #8 out. This is probably one of the best unit aviable.

Performer RPM
Duration at .050 Lift: Intake 234° Exhaust 244°
Lobe Separation: 112°
Lift at cam: Intake .325 Exhaust .340 Intake Centerline: 107°
Lift at valve: Intake .488 Exhaust .510


Ron