I stand by answer!! It is a Nova Engine, no doubt what so ever for me!!
As for the other engine being Chevelle I can't say just by where the VIN code is stamped allthough Camaro plants were doing this before others but it appeared to be to speed operations because engine accessories were having to be removed to stamp the code on some models. As you can see from the image there were quite a few assembly plants putting cars together. They did not always do things in harmony. The reason for stamping the VIn code on the rough surface was to prevent theft (called the cop VIN). For someone to alter the VIn they would have to disturb the rough surface and would be a dead give away of tampering.
274985 is just a sequence number, i.e. the last 6 digits from the Nova's VIN. It has no reference to the car line what so ever, the books are not always right, they very often changed the methods because of sellin more cars than predicted. Just because that 2 does not agree you cannot throw out the other code meanings. The VIN code on the engine is in a diffferent form that on the VIN tag and title.
Here's what my book says on the Engine numbers.
I scanned in some info about this, take a look and print it out (it will gone soon). I had to cram the info onto one sheet to make is easy for me.
www.synthetic-oil.com/images/70.jpg
[Edited by elcamino (01-26-2001 at 08:33 AM).]