What is the functional/performance difference between an Edelbrock performer intake and the aluminum four barrel Ford was putting on mustangs in the early to mid 80s?
The Mustang GT intake was good to wake up a tame stock engine.... light compression, stock cam, etc. ... I wouldn't pay any more than $50 for one. You will need to find a carb spacer big enough to block off the heat riser next to the carb too, or that becomes one giant vacuum leak. Mr. Gasket made one in the 90s ... not sure now. If you are thinking any other mods, go aftermarket. Performer is OK for a mid-level all-around daily driver engine, Performer RPM is a step up (again matched to a bigger cam, etc.), but I would go straight to the Air Gap if thinking about the RPM. I have a Performer on my 351, mainly due to the struggle of fitting that engine under the hood. Otherwise I would have an Air Gap, which is taller. It gives up a bit of HP, but makes excellent torque. A 1" spacer helps wake it up a bit, too. Some guys like Weiands, too.
I will be putting this on an '87 5.0 HO mustang engine that was originally fuel injected. It will most likely be paired with the Edelbrock 1406 600 cfm carb. The engine will otherwise be as it was on the 'stang, except for what I have to change to fit it in my mav (timing chain cover, oil pan and headers to fit). I will use the car as a semi daily driver with frequent 90 mile round trip commutes, so I am looking for some economy. I won't do any racing at all, but I want it to be fun/interesting to drive. I really appreciate the information!