My 340 in my 66 developed issues :-(

The passenger side is not the hipo manifold. Keep the driver side and look for a magnum version for the passenger side. One member on here sells them.

Then get the pipes to fit them here: TTi Exhaust Component Parts

Yes! This guy sells them. Start a conversation with him to see if he has any. [SOLD] - 340 Driver's LARGE HOLE Exhaust Manifold