Interesting question. I just swapped a spider radiator for a spider radiator this morning. They are different depending upon the year because of where the over flow tank is located. A 74 spider radiator has its over flow on the intake side and a 76 has the overflow on the exhaust side. Just a matter of rerouting the overflow hose. The hose doesn't look right, but it works. Best if you can swap out the top tanks for it to be correct and check where the overflow pipe comes out.
I thought I have seen some pictures that look like it can be done. The radiator cap is located in different places. The spider is extended toward the engine. (I think to clear the hood). My real problem is that my current radiator is junk and I would prefer to pick up a good used unit instead of the $$$ to re-core the old one.