sowaxeman

I did this once way back in the day on my '82 but I don't remember how I did or if it was even right. I want to take off the factory Y pipe under my '85 and put on a true dual off road H pipe (yes I have a new dual hump cross member). My question is the O2/smog pipe that comes out behind the cat and runs back up to the smog system- what do I do with it? Do I need to fab a way to attach it to the O2 bung on the o/r pipe, or do I just cut it off and cap it??

sowaxeman

Nobody's familiar with this?

P Zero

An h-pipe should bolt right up. As for the A.I.R. tube, I just removed the smog pump alltogether and plugged the hole for the pipe. And I used autolite 45 spark plugs to plug up the O2 holes. Its easy, its all direct bolt in.
-P.

sowaxeman

Spark Plugs eh? Cool! Back when I did my '82 I went to the hardware store and was able to find some plugs in the plumbing section that matched the threads. But spark plugs seem much cooler I don't want to remove the smog pump at this point because I want the engine bay to remain stock, but that is definitely something I would consider in the future when I pull the engine and do a repaint. But for now I want toshow asstock/un-restored.

P Zero

In that case your might have to get some tubing and run it to the H-pipe for AIR tube. Im sure you can find some sort of high heat flex tubing somewhere thatll match up. Or measure out the bends and have some tubing bent for you. ANd removing the smog pump is pretty easy actually, theres a bracket on the bottom (if I remember right), and one long through bolt on the top. Takes like 5mins to remove it. When I did mine I also removed the a/c and put on a UD pulley on the crank only. The 85's came with a 130amp alt stock so you dont need to swap any other pullies other than the crank. If you keep the a/c ps bracket youd need a 71.5" belt and if you get teh non-a/c ps bracket itll take a 69.5" belt, thats with the UD pulley. Good luck .
-P.

HACKGT350

i think you might wanna get a new set of headers to go with the h-pipe those stock headers suck my nuts as for the o2 sensors just get those plugs again from the hardware store thats what plugged mine and the air tube i had welded shut

gspfunk

I ask this at the risk of sounding ignorant, but: Why not just get larger diameter pipes (Y and exhaust)? You would have better exhaust scavenging/merging than an H pipe, or so it would seem from the LT1/LS1 setups. But you wouldn't have dual exhaust...