longlive289s

wanted to upgrade this sucker (actually mine has a hair line fracture in it on the outlet tube...no idea how that happened) and was wondering

1) It says in my little mustang bible that delivery pressure is 4.5 to 5.5 lbf/in2. does this need to remain the same? or would it cause any problems uping the pressure. I do have a brand new holley street avenger. Seems that upgrades are more around the 6.5 lbf/in2 area

2) can some explain the whole free flow rate?
- First, what is the stock gph on a 66 v8 mechanical fuel pump
- 2nd, would I really see any difference in anything uping the gph? Unfortunately I dont have a dyno and an uncover fuel bowl in carb to look to see if it's getting empty. tho i figure the car would shudder if it was.

3) How would one go about putting a electrical pump in? I'm gonna go mechanical but I'm just curious. Is their a block off plate that you would have to buy to block the hole a mechanical one uses? or does it just bolt up to the same spot.....just without a lever?

4) I was roaming around Summit Racing and a bunch of those holley/edelbrock pumps dont have levers in their pics but say they are mechanical.

5) lastly (phew....i keep thinking of more q's) http://www.summitracing.com/parts/HLY-12-289-11/ (also good pick of what I mean for q #4) But then I see this http://www.summitracing.com/parts/CRT-M6588/
$60 cheaper and looks exactly like what I have now.....what gives?

thanks guys

blue66mustang

I have the same pump it is indeed mechanical with a lever. It's just not in the picture. It works great with my HOLLEY carb.

67mustang302

I'm running an Edelbrock mechanical.

Free flow is how many gph the pump flows maximum, and basically determines how much horsepower it can support.

Not sure what the stock flow is, but it's actually not too bad.

Pressure is rather important, too little and the carb won't get fed enough fuel under WOT and you could lean out, too much and you flood the carb. My Edelbrock is internally regulated and seems accurate, hasn't ever needed a regulator in the line. It's set at 6.5psi iirc.

Gun Jam

1) You can run 6 PSI and be fine
2) should be the gallons per hour the pump can deliver. No you wont see a difference unless you are making 500 hp
4) Not shown in picture
5) I like the holly design better than the cheep carter. But I like this one the goodest http://www.summitracing.com/parts/CRT-M5904P/You spend a few bucks on quality install that **** and go about your business. I got that one right there daily driven for the last 5 years never a bit of trouble.

-Gun