Osco risers for 470 motors

[Benny67]

I'm trying to figure out if an osco 0879 riser can be used on one of my 470 motors.

I picked one up on eBay to keep as a spare (got it for $100) but realized after I purchased it theres two different ones,one for aluminum and one for cast iron manifolds.

Does anyone know if they are interchangable?

I believe the osco 0879 is for a cast iron manifold

My motors are 1987 and I'm assuming their aluminum manifolds.

 

[nola mike]

The reservoirs for the cast and aluminum manifolds have different Merc part numbers. They also have different manifold to reservoir gaskets, so I'd guess they aren't interchangeable.