I couldn't find the old thread we all talked about this, so created this new one.
I put on the SPD Y pipe yesterday. Only took a couple of hours, the vast majority of which is cutting, fitting, cut a little more, fit some more.
Anyhow, that is all I changed was the Y-pipe. In the previous thread I had mentioned that 2 years ago I had replaced the P/S manifold studs with the improved Ford pieces, due to the originals breaking. About a year after that I developed another leak and figured the bolts had snapped yet again. I was wrong! The manifold had a small rust hole / crack in the bottom near the block, but I was able to weld that up.
Eventually I will be adding a new muffler, the stock one is leaking where the straps hold the heat shield.
But I did nothing but the Y-pipe so I could verify its benefits.
Sound: I think the truck has a little deeper tone at idle. While driving, you can hear the exhaust a little in the Y-pipe area under the floor. Its not a leak, you can just hear the hollow sound of exhaust flowing through the pipe.
Performance: Off-idle throttle response is much more instantaneous. At low RPM I can feel a big difference. I mashed it a few times up to about 60mph, feels like the motor revs a little quicker. I have not towed anything yet, and I think that is where I will see a big improvement.
Does it add the claimed 33 hp? I don't know, thats a lot for just a Y-pipe upgrade but the stock piece HAS to kill at least 15hp.
I am very happy with the change, recommend it to anyone's truck with that piece of poo stock pipe.