What was more common?

[Buzzard Wing]

Mmmmm interesting.

I have one of each.
Replacing the hacked up (184?) exhaust with an underslung was a bit of a problem, but it is nice to have the exhaust behind you. It could be considered NOTA (none of the above) becuase it was just wrong:
http://i2.photobucket.com/albums/y40/Bu ... CN3424.jpg

As for the regular exhaust.... with the flapper facing forward it stays open on the highway (on a trailer, of course) but it does make sense that it should face forward? The down side is that it hit my shoplight when I pulled it in the garage, so there is less vertical clearance.

Until I git r' done.... I won't have much of an opinion, but I do like it out of the way.

[RustyVT]

Without knowing any better, I always assumed the exhaust direction was an option, the key factor in preference being what you expected to do with the tractor. A veggy farm here has a cobbled-up verticle exhaust on a 60s model cub originally underslung because the grower didn't want hot exhaust blowing onto the leaves of the crops he was cultivating or spraying late in the season when they were tall. For mowing lawns and snowplowing, I wouldn't want to have the exhaust at "nose level" or be in the way of tree branches and garage doors. Though it would be nice to have something hit the branches before my face, I understand the verticle exhaust does a nice job of springing them for direct impact......