This may sound like a dumb question, but I've heard that if you use an in-line electric pump, you could actually leave the factory fuel pump in place and simply pump fuel through it. Also, I'm confused on the use of fuel pressure regulators on carbed engines(I'm using a Carter AFB 600cfm.) I've been told that you don't need a regulator if you run a lower output pump. Is there any truth to this? I'm in the process of buying misc parts for the conversion and I'd like to find out for certain. Thanks guys...

GTBastard, the 6 cyl pump has too much pressure, >50lbs, I believe. You can use/install the 4cyl pump and use a regulator. The 4cyl puts out about 15lbs. Optimally, with a carb, you would 'regulate' the fuel pressure down to 5-7 lbs. Not sure about an ouside(inline) pump, 'pumps push alot more than pull' and you may in time burn it out!
Sandy

GT,

The prior posts are correct. I had to switch out my stock V6 pump for a 4 cylinder pump when I did my conversion. Even then, I had to install a regulator to reduce the pressure to 6 psi. max. If you don't use the regulator, fuel will be pushed past the idle, intermediate and primaries.

If you want to use the stock pump, get a regulator with a by-pass port. Its much easier to change. Otherwise, you will have to drop your tank and change the pump. Its not really difficult -- just a hassle. I spent this weekend doing just that after my pump failed. You can get a by-pass regulator from Mallory (part no. 4309).

Good Luck

Farknocker

GT Bastard
I put a T in my fuel lines and jetted the return line in order to pick off approximately 5lbs of pressure to the carb. I have a vacuum/pressure guage to measure this and drilled the return jet till the gauge read in the range I wanted. Been working since sometime in the summer of 1999. I was using a static in-line regulator till the short piece of hose that connects the in-tank pump to the line out burst and I lost down to 1lbs of pressure. The hose may have been just getting old but I reckined it may have stressed the line out by using a regulator that had no return line so I figured I'd try a new approach. So far so good and I had the plumbing already in the shop to do it so it was inexspensive for me also.