On my '86 I kept the cats and deleted the muffler and resonator. The result was a great exhaust note but not too loud. I also did CVPI shocks. Those along with good tires run at around 36 psi got me fairly decent handling. It was the cheapest car in terms of cents per mile that I had, but it would be hard to duplicate that feat with today's gas prices. Mine averaged 18 mpg. The 302 was less efficient than the 4.6 that replaced it, the aerodynamics of the '86 were "box", and I drive like Ayrton Senna chasing Alain Prost on the penultimate lap at Suzuka.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.