My Mom's Car an Antique??? in General Discussion Posted April 4, 2010 Another thing is you just DONT try and accelerate up a "mild grade" in overdrive. At least if the car has the typical 2.73 gears out back. That's what my '87 Crown Vic daily driver has. Worthless. In all honesty for them being called "highway" gears, they aren't great on the highway. Id like to know why Ford didnt make an EFI 351 standard for those cars. The S.O. (standard output) 150 horse 5.0 Liter was bad enough in say a cougar or tbird, but throw another 400-500 lbs on to about 2 tons with one of these boats....the poor thing can't move it along to save its life.Now a friend used to have an 89 grand marq and that got around no problem...he must have had 3.08s or 3.27s in it. I think I see a rear-axle teardown in my future!!