Are any parts interchangeable between marlins, rossi's or henrys? Fer instance, springs or levers? I understand that parts can be found pretty easily fer most of them. I was just curious to see if there might be any common parts used that could be switched between them. I own a marlin right now, but lets say there is a place i can easily get parts fer a henry and i need a hammer spring fer my marlin. Fer the convience it would be easier to go to the place that has henry parts. Like i said, i am just curious as plenty of other guns have some type of parts that can be interchanged.

Rossis are copies of Winchesters.  Marlin is it's own brand.  Henry may be an 1866 copy, also not compatible w/ Marlin.  I stand corrected.

Most Henry centerfires are actually clones of the round-bolt Marlin action. I don't know about parts interchangeability, but the actions are functionally very similar with the exception of the Henry transfer bar safety versus the Marlin half-cock notch, I believe.

I would say for the most part no, that would be like asking if Chevy cylinder heads will fit on a Ford small block.

Thats true about the cylinder heads. However, pistons, rods and rocker springs can all be used to and extent between the two depending on the type of engine build.