I just finished installing a Heartthrob kit yesterday. It's their P/N 4144SK with stock mufflers and tailpipes exiting at the sides behind the rear wheels. Since my 82 C10 uses 96-00 5.7L Vortec exhaust manifolds, I had to modify the down pipes, so I can't attest to their fit with stock manifolds.
Pros: Thick wall 16 gauge aluminized pipe, smooth mandrel bends, two extra pipe sections for very long wheelbase trucks.
Con: I didn't see any way to make use of the short hangers. They are apparently designed to mount horizontally between clamps and frame rails, but they aren't long enough to do that. So I ended up buying flexible hangers from a parts store, and hung the pipes vertically from a cross rail just before the mufflers, and from the frame rails to the tailpipes.
Also, their "stock" mufflers are on the loud side, and sound more like turbo mufflers. The noise is amplified by the side-exit pipes bouncing sound off cars and curbs. For whatever reason, the kit with pipes that run straight back to the bumper cost more, even though there are fewer bends and should be cheaper to make.
On another note, I used stainless band clamps at the pipe and muffler junctions for ease of future disassembly (6 x $7.97 at Summit)
Overall, I got a lot of nice pipe and two mufflers for a very good price at
Auto Accessories Garage. I paid around $218 including shipping using a discount coupon. Total spent was less than $300 including stainless clamps and hangers. Average price at local muffler shops to do the same work with
crush bends was $650. And they typically want to weld everything together.