Exhausting day at the Y

Guys:

I've spent the past couple months reviving the '74 Valiant in my sig. Yes, just like the one you scrapped a while back, except much nicer.

I had a huge exhaust leak repaired recently, pretty much the entire pipe from the y back to the muffler. Well, after getting it done it was discovered that was only HALF of the huge leak.

The other half is at the top of the crossover directly underneath the oil pan. Never seen one rot there. The superheated exhaust gases are scorching the oil pan and it can't be good for the oil temp either.

So quick question: Will a y-pipe from an M-body, specifically about an '85 Fifth Avenue, fit on there? I know some of you can't remember or mentally blocked out what stock 318 manifolds look like:mrgreen: so I'll describe:

The passenger is the one looks like a very shallow w with a center dump. The driver side is upswept along the valve cover, then dips down past the back corner of the head. Like a 340 manifold that didn't quite get there.

An M-body is the only V8-powered passenger car in the yards around here, at least the self-service ones I go to. There may be one A-body show up a year, that's it. Used to be you could buy replacement y-pipes but that's been a while. I could possibly have one constructed, but that is severely testing the capabilities of the muffler shops in this area, and they'll certainly charge me for the effort.

And...not being rude, but not doing duals, headers, anything else..period. I already have a modified A-body that has that stuff.

I posted a want ad for a used y-pipe but I doubt I'll get a response, I never do.


Thanks for any help.