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What fuel pump you guys using for your modded engines? Electric or mechanical?
I'm down to the last decision I need to make before I start ordering parts and maxing out the credit card I took out specifically for parts lol.

I have a stock 71 Boss with headers. Going with a blue thunder intake and demon 750 annular carb. I'm boxing away the correct original parts meant for trailer queen driving Undecided and trying to mildly increase performance.

My main concern is fuel boiling. I live in one of the hottest cities in the U.S. and we all know these engines tend to run hot. I already have a 1/2 wood spacer ready for the composite carb. Do mechanical fuel pumps tend to boil fuel easier than electrics?

I'm trying to keep a stock look appearance and the only decent mechanical pump I can find is the one by RobbMc. Anybody using one?

I am also considering a Holley electric fuel pump, the gerotor style for quietness.
I am running a stock replacement mechanical fuel pump on my 408 Cleveland with almost 600HP with no issues. I am also running an 850 or 950 quick fuel carb. Feeds it just fine.


1971 Mach 1
408C Stroker
C4 w/3,000 stall
8.8" Rear w/3.73's
Disc brakes all way around.

[Image: 28ivsix.png]

I'm using electric. I initially started out with a Holley "Black" rotary vane fuel pump, but it was LOUD! (You can hear the loud 'buzzing' noise just before it starts - never goes away, and resonates through the entire car inside)


Here's the old Holley pump (I had run the plumbing a bit different to make sure it didn't hit anything, by using a 90 degree elbow... but never got a pic:
[Image: 552200_515739831770273_135038063_n.jpg?o...ef37cf430b]

Here's the new Holley solenoid style pump - fits even better and is QUIET!
[Image: 11000308_1050382174972700_8431350656838990094_o.jpg]

This is the rock guard/cover I made for it using a piece of an undercarriage panel from a Jetta (or something) someone left at the Auto Hobby Shop after changing their oil... never came back for it after 6 months, so I figured it was fair game. Wink Big Grin
[Image: 11130387_1050382178306033_1638772545445362473_o.jpg]

Hope this helps.

And no, tragically I haven't gotten around to cleaning all the overspray and bondo-dust off the undercarriage yet. Shy


[Image: mach1sig2.gif]
Fuel under pressure takes a lot higher temperature to vaporize (vapor lock). As long as the fuel line from the tank to the mechanical pump isn't near or in contact with anything hot, and as long as the sock in the tank is clean (fuel under vacuum/suction vaporizes at a lower temperature) the mechanical pump should be fine. Vapor lock generally takes place between the tank and the engine mounted pump. An electric pump mounted near the fuel tank will pretty much eliminate any possibility of vapor lock.

I am concerned about the wood spacer for the carburetor (unless you are talking about the laminated one from Edelbrock), wood absorbs fuel, and contracts and expands with humidity changes, making it difficult to maintain proper torque on the mounting studs/nuts. You can get a phenolic or plastic spacer for insulation.

“If you can't explain it simply, you don't understand it well enough.”
--Albert Einstein
Yes it the Edelbrock laminated spacer.
I have the RobbMC pump on my Boss. I tried the Holly electric first. Changed mounting positions 2 or 3 times. At that time the RobbMC was on backorder for 7 or 8 months. They had lost their supplier of the arms they used in the Ford pumps. Their pump ended all my problems.

The problem with the Holly electric was the car would run out of gas at about 2 miles. Of course, this always happened when I was on it. If i ran it on low rpm's around town it would run fine. Take off out of town with any mount of rpm's, it would run for about 2 miles and die. Very frustrating until I figured out that it was just running out of fuel. Wait 4 minutes and it would start.

Will sell the electric Holly for $50.00. It has about 18 miles on it. Looks like new.

I use before a new Holley (blue)with regulator, DON'T buy this pump it makes a LOT of noise.

If you want to use a electric pump take a Mallory, but why a electric pump... all Mustang runs great (+40) years with mechanical pumps.
I had the same question not too long ago, I built a "BOSS" style cleveland for my car, around 350hp, and my mechanical is working just fine!! And it looks stock!!Big Grin
Looks like I'm going with the RobbMC. Are you using hardline to the pump or flex hose? What size?
I am running hardline up to the engine bay, short piece of rubber hose to pump. Then stainless braided from pump to carb.


1971 Mach 1
408C Stroker
C4 w/3,000 stall
8.8" Rear w/3.73's
Disc brakes all way around.

[Image: 28ivsix.png]

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