Also, V8 Mustangs built after 1999 and CVs/Grand Marquis built after 2001 have what they call "Performance Improved" cylinder heads, and revised intake manifolds. These made as much as 260 horsepower in Mustang GT trim. You can swap over just the intake manifold for a few extra ponies, swap in an entire PI engine for about 50 extra horsepower, or if you're feeling really ambitious, swap the PI heads onto your non-PI shortblock.
Non-PI engines had a smaller piston dish and a bigger combustion chamber in the head, as compared to the PI engines. So if you put the small chamber PI heads on the small dish non-PI pistons, you get a higher compression ratio, which means more horsepower AND slightly better fuel economy, at the expense of having to run premium fuel in your car.
Also, Ford 4.6L motors respond very well to supercharging. This is probably the most cost-effective way of adding low end torque to your motor. (It won't work with the PI head/non-PI piston build, though. You'd have too much cylinder pressure and blow something up).
Finally, all Ford 4.6's made between 1996 and the middle of 2001 had an all-plastic intake manifold that had a design defect causing the manifold to crack, resulting in a massive antifreeze leak right below the alternator. Midyear 2001, Ford swapped over to a revised intake with an aluminum coolant crossover tub right beneath the radiator. Make sure your 1997 has had this newer intake manifold fitted. If not, replace it now, because it will leak. It's easy to tell if you have the new manifold. You can see the aluminum coolant crossover right underneath the alternator.
Sounds like a D-derby car to me!
Like in the comment there a sleeper could be fun.. since the GM and the crown vic are basically the same car parts may be plentiful. first thing I would do is strip the weight take everything out you dont need. then allow that motor to breath larger exhaust and if you can supercharge it.. since it is rear wheel mess with the gears it may not be able to go faster than 80 but it will sure get there fast..
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I know some of you might be saying that a Grand Marquis wasn't meant to go fast, but I already have a daily driver and the guy I bought it off sold it to me for $150 and some labor (great condition, the only thing I need to replace is a window regulator), so why not? I'm not expecting crazy numbers here. Just a little budget build to keep busy. Any thoughts here?
