[War_Wagon]

Well it's up to you if you want to experiment with setting it more advanced than 10 degrees. If you only run 87 octane fuel, you could try it at 12 or 13 degrees advanced and see if 1. it pings, and 2. you get an improvement in mpgs. But make sure that it is at least at 10 degrees.

If your old cats were plugged up then yes an H-pipe would have made a big improvement over them. It's just that those cars with stock gears like the extra torque that a little bit of back pressure can provide. I have seen people put an H-pipe with big 2.5 inch mufflers and tailpipes in an otherwise stock Mustang and it actually slows them down at the track. My '93 is quicker with the cats in it than without them, as backwards as that sounds. For mileage it translates into needing less throttle to get rolling. If you still have the stock 2.25 inch mufflers and tail pipes, I would leave them there, their smaller size is probably helping you out.