That's a pair of 70s 340 manifolds. The driver's side is large hole (2 1/4") but the passenger 340 (in the 70s) was only (1 7/8") hole. They will work but the passenger's side won't flow nearly as good as the driver's side. I've never been able to figure out why Mopar made the 1970s passenger's side 340 manifold smaller but left the driver's side bigger???
