Hi, the "street race" tips are longer because there is more room for them due to the way the system is bent. On the Mach system the 90 degree tails don't offer enough room to use the same tips. When the car is on the ground and you look at the shorter tips they look really good and appropriate to the car.
The cat: Lifting the engine isn't as hard as it sounds. Our hoist lifts the car by all four wheels, they are drive on ramps. 1) Remove 15 ml. nut from lower right side motor mount.
2) Support engine at motor mount brace where it fastens to the block ( this is a real strong point) with a heavy duty jack stand. 3) Let hoist down about 1 to 1 1/2 inches. This raises the engine and allows enough room to get the cat out. 4) Twist and wiggle the cat out from the underneath side of the car. Be careful, the body panel where you do have to be to wiggle the cat out has very sharp burrs on it. If Those burrs are anything like they were on Shabbys car you may want to file them down before starting. 5) Slide new cat in and reverse process.
Thanks.