Are 4g63 6 bolt engine parts interchangeable with the 7 bolt 4g63?

[saber85]

I have a 1994 mitsubishi eclipse GS 2.0 n/t.
I just swapped out my timing belt cover, and the 7 bolt cover I bought didn't fit on the engine properly. I had to cut off 2 tiny pieces on each of the bottom corners, in order for it to fit nicely. Looks good, covers all still, so will still protect, but I shouldn't have had to cut and shave anything off. Also, the new cover had an extra bolt hole on the bottom, by the flywheel. Then I noticed the old timing belt cover I took off belonged to a 1g(a) eclipse model (pre 4/92). So I believe the previous owner installed a 6 bolt engine on my 1994 eclipse 2L n/t 1g(b) model. I am not sure what year eclipse the engine belongs to.

When I buy car parts at auto parts stores, I have been telling them I have a 94 eclipse, which I now know my engine is not a 94 engine, otherwise the new 7 bolt engine cover would have fit. So I want to know if most parts are interchangeable? I already have bought a few major mechanical parts that connect to the engine (belts, alternator, hydraulic adjuster for timing belt, water pump, tune-up parts) and they work, but they were bought for a 1994 eclipse 7 bolt, not the 1g(a) 6 bolt engine. Notice though, I haven't bought any internals yet. Is it ok if I still tell the auto parts store, I need parts for a 1994 eclipse? Or have I just been lucky that the few things I bought were interchangeable? I might need new valves...

Better yet, what parts are not interchangeable, between a 6 bolt and 7 bolt 1g engine? I'm thinking everything but some internals and some covers, should be an exact fit for all 1g models. I hope that's the only thing that is really different, besides the 7 bolts that connect the flywheel to crankshaft, and the beefier connecting rods. Can I just say give me parts for a 1991, when it comes to internal engine parts?