Cadillac Repair: fuel injector, 1979 cadillac seville, cadillac seville

Question
Hi Kevin,  I just bought a 1979 Cadillac Seville Opera Coupe with the extended hood.  It ran very roughly.  My mechanic tuned it up, straightened out a lot of little problems, leaks, etc. but is stuck on the one major problem still remaining.  Although the engine runs much smoother now, the # 1 cylinder is not working.  My mechanic thinks a new fuel injector could solve the problem because everything else seems to be in order.  It has a 350 Oldsmobile engine.  I have three questions:  1.  I heard about 300 Opera Coupes were made.  Does that mean per year in the late 70s and early 80s or altogether?  2.  Where can I get a hold of a good fuel injector for this engine?  3.  Would you guess that is the problem or would you look elsewhere?  If so, where?  
Thank you very very much.  Bob

Answer
Bob,
There were a number of aftermarket coachbuilders who made customized versions of the Eldorado and Seville back in those days. Unless you can ID the actual coachbuilder, it's hard to even know what type of car you have, let alone give you any hard/fast info on it.
As for the drivability issue, your mechanic should be able to verify whether the injector is bad by doing a simple flow test on it. Matter of fact, I'd suggest doing all 8 to compare. At that point, you can decide whether you need to troubleshoot further or replace injector(s) based on the results of the test.