just picked up a 1982 Firebird S/E, it has alot of options including Viscount PMD seats, ttops, power windows, rear hatch wiper, etc i have a few questions that i couldnt find answers to in searches the 2.5 is a pontiac motor correct? What parts are interchangeable from other engines? What header would fit on this head? (Same style as pontiac V8?) also, there is something in white pen on the rad support it says "#6 3-19-82" any significance or did they all have that?

Yes, it's a Pontiac motor: basically half of a 301, kind of like the way a Chevy 4.3 V6 is ¾ of a 350. It's 151 CID. Some internal parts may well interchange, such as pistons and rods.

I don't know about interchange though. Seems like you could visually compare the head to a 301 head, and see if the flange is the same; and if so, then maybe a header could be made up for it, using the flange from a Pontiac V8 one and re-routing the tubes as required.

Or the pen... don't know about that either.

Header? What is the point of that?

just wondering, i need to change the exhaust manifold gasket and the collector bolts on the stock manifold so might as well while i have it torn apart

The 2.5L 4-cyl Iron Duke(Tech IV) is it's own design and has nothing in common with the tradition Pontiac V8 engine(unlike the "half a 389" 194 cu. in. Pontiac 4-cyl produced in the early 60's)

The FWD version of the Tech IV gained a roller valvetrain and balance shaft system installed in the oil pan in the late 80's. I'm not sure if any of this would swap over to an early 80's RWD version but it would make a nice boost if it does.