When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
5.0L (1979-1995) MustangTechnical discussions on 5.0 Liter Mustangs within. This does not include the 5.0 from the 2011 Mustang GT. That information is in the 2005-1011 section.
Dan, with your mods I would try at least 42 psi on the fuel system if not higher to make sure it ain't running lean. stock ECU's tend to run on the lean side most of the time so you want to be careful not to go too lean. of course the best way to set it would be to get it on a dyno with an air/fuel meter plugged into the tailpipe. once I installed an adjustable regulator on my '88, I set it at 50 psi with the pump on and engine off and this gave me 44 psi at WOT going down the track and my plugs looked pretty good too.