gas mileage questions

Best gas mileage??? That's a first. Since you're going to the dyno anyway.... tune it to the factory 14.7 AFR across the powerband then maybe have them juice it for maximize horse power at WOT. So long as you keep your foot out of it then your gas mileage should be about as good as it's gonna get. You still running SD or MAF? If you're still running SD then getting a chip programmed to deal with that cam will make a world of difference in your fuel mileage. I imagine that with the 24 lb injectors, the E cam, and the stock EEC program that you're probably running rich as hell right now (stock regulator + decreased vac = too much fuel pressure + larger larger injectors = too much fuel (assuming a stock EEC program and fuel tables)). Just getting a custom chip should make a big difference. My suggestion: Tune it for power and let the fuel mileage take care of itself. Another option is to get multiprogram chip with two programs. One for power and a flip of a switch for fuel economy.

I don't think the EGr palte will make much of a difference in your fuel mileage and if your air pump it gone it's pretty mucha moot point anyway. Check your T-stat... if you've got a 160 in you should consider ditching it for a 180. The dyno should tell you the rest.

FWIW...the Cobra intake does not use an EGR spacer. It's 'built in' for lack of a better term.