po51 21 Report post Posted May 19, 2015 I’m getting ready to rebuild my 351W into a 408 stroker for my 69 stang. I would like to keep a mechanical fuel pump and upgrade to a Holley pump. A friend suggested I go with an electric pump, I would prefer to stay with the mechanical pump, any issues with this? Quote Share this post Link to post Share on other sites
Rsmach1 71 Report post Posted May 19, 2015 Nothing wrong with a mechanical pump, the only issue I've had with the holley crome pump is the diaphragm coming loose in the pump body. Edit; plus you don't have to worry about installing an inertia shut off switch. Quote Share this post Link to post Share on other sites
coz 108 Report post Posted May 19, 2015 Yep - nothing wrong with a mechanical fuel pump. I run the 110 gallon Holley and it works fine. There are some fancier pumps out there but the Holley seems fine. Plus don't have to dork with regulators / return lines https://www.holley.com/products/fuel_systems/fuel_pumps_regulators_and_filters/fuel_pumps/carbureted_mechanical_pumps/parts/12-289-11 Quote Share this post Link to post Share on other sites
jholmes217 65 Report post Posted May 19, 2015 No issues with mechanical pumps. You may need a fuel pressure regulator. Holley, Autolite, and Motorcraft normally don't like fuel pressure higher than 5 or 6 psi. I put a Carter on my 428 Cobra Jet, and it started spitting fuel out of the vent tube. After I put a regulator on and set the fuel pressure, it worked fine. I'd do some research 1st and find out if it is resistant to ethanol that is used in modern gas. Ethanol is hard on rubber, and many mechanical fuel pumps have a rubber diaphragm. Quote Share this post Link to post Share on other sites
MikeStang 247 Report post Posted May 19, 2015 Wish I had went Mechanical but my timing cover is for a reverse rotation water pump and has no provisions for one so I had to use an electric pump. The Edelbrock Quiet-Flo pumps work pretty good and are pretty darn quiet. Quote Share this post Link to post Share on other sites
SA69mach 39 Report post Posted May 20, 2015 I have the Holley 110 gph pump on my 68 Camaro with a built BBC. It has no trouble keeping up with fuel demands, and no problem with overpressure on the 770 Holley SA carburetor. I think it would be comparative to your 408 in terms of fuel requirements. What size carburetor are you using? Quote Share this post Link to post Share on other sites
GypsyR 32 Report post Posted May 20, 2015 An FYI for MikeStang. Should you care to take the trouble, you can swap your timing cover for a 1985 Mustang 5.0 cover and have a mechanical fuel pump while keeping reverse rotation. I've run across other timing covers that were reverse and had the mounts for the fuel pump drilled and tapped but the center hole for the pump arm was never "knocked out". Few minutes with a Dremel took care of that. Just saying there are those options out there. If you are all set up with an electric pump you're happy with that's fine too. I'm good with either pump style myself, just depends on the circumstances. Quote Share this post Link to post Share on other sites
MikeStang 247 Report post Posted May 20, 2015 Good info Gypsy...may look into getting one and swapping out Quote Share this post Link to post Share on other sites
BandBSTANGS 15 Report post Posted May 20, 2015 I use a Robby Mac pump on my Cleveland. Good to 550 hp and can be rebuilt to support 1000 hp Quote Share this post Link to post Share on other sites
BandBSTANGS 15 Report post Posted May 21, 2015 better photos of pump Quote Share this post Link to post Share on other sites
MikeStang 247 Report post Posted May 21, 2015 Nice Pump BandBstangs Quote Share this post Link to post Share on other sites
mustangmike6996 34 Report post Posted May 30, 2015 Im using the Holley on my 331. No issues so far. Quote Share this post Link to post Share on other sites
