Anyone ever see this before?
 

This just showed up on e-bay. I had seen the cast dump elbows for the cast tri-Y headers but had never seen one for the stock manifolds. Wonder where the left side is.

Turbo 301?

That is a Tri-5 manifold with single exhaust. The pipe crosses from the driver's side to the Pass side. Manifolds for the 3 '55,'56 & '57/'58 are each different.

Looks like the rt. bank exhaust manifold of 1959-60 389 single exhaust; but I've seen them on 55-56-57 but different. Starting in 61 they brought the left bank tube over and welded it to the rt side.
http://i281.photobucket.com/albums/k...c/DSC02449.jpg


check this out:
http://www.pontiacsafari.com/MPC/Pages/page_0178.jpg

Interesting thread.

Thanks, pfilean, for starting it.

Learned something today, good thread.

Similar to Oldsmobile's funky crossover setup on some of their engines, which they used for a long time...