Exhaust pipes for 1985 Thunderbird

June 2, 2007 5:06 PM

When buying exhaust flex pipes like these, to fit over an H-pipe with a diameter of 2.5", would you buy the flex pipes with the 2.5" outlet diameter or do you need something bigger?

My brother ended up having to cut the H-pipe with a Sawzall to remove the stock headers on his '85 Thunderbird. Now he's having problems installing the new ones. He doesn't want to buy a new H-pipe (even though 2 of the flex pipes he wants instead would cost just as much, but whatever), but we're not sure which diameter flex pipe to order. I say he should order the diameter that matches the diameter of the existing h-pipe, but he wants to order the 3" pipes figuring he'll be able to clamp them or something. Help me help him not waste any more of his money.

posted by Venadium to travel & transportation (1 comment total)

He needs the same size, but the h-pipe has to be expanded at the connecting end using a special exhaust expander tool so it can fit over the flex bit. A 3" would be a serious waste of money. You can find the tools cheaply if you look around or an exhaust place might do it for you. Just remember, it's usually best to weld the resulting joint for a good seal, clamps notwithstanding.
posted by IronLizard at 1:12 AM on June 3, 2007