'71 198 swap to a '76 225 - help identifying noise?

The original 198 in my '71 Valiant lost cylinder #6, so we found a decent '76 225 and swapped it in today. Mounts were different and there was a bunch of additional emissions stuff which we removed, but otherwise went pretty darn well! These engines are so straightforward, love it!

Anyways... it is making a slight noise / tick. Can any highly trained ear out there point me in the right direction? Don't think it's simple exhaust leak.


You do know the rods out of that 198 motor are worth saving. Even if only 5 of them are still good. There is always a market for the 198 rods.