The LT1 motors are notoriously reliable apart from one little problem.....the OptiSpark ignitions. For whatever reason, GM mounted the ignition in a very poor spot where it can get wet and short out. They are a pain to replace and not exactly cheap. 

That said, LS1 motors are also reliable and make more power. However, looking at longevity, the LT1's are nearly indestructible. Both motors are excellent.

As for the V6, the newer V6 models were more reliable. The drivetrain wasn't typically the.problem on those catfish Camaros. It was the fact that everything else on the car falls apart that was the issue.

@Mod_Man said it best. Everything he said is exactly correct. I’m a 4th Gen Fan. I’ve had two, 3.4L V6 5-Speed & currently have the 5.7L V8 LT1 (Auto) and as mentioned I hate the optispark ignition system it’ll definitely leave you stranded or give performance issues if you don’t check under the hood every so often to make sure that water pump isn’t leaking YET 🤦‍♂️ But other than that, I love it. Last thing to mention is that if you’re going to get one I’d aim for manual transmission 5/6 speed. Those 4L60E auto’s will leave you with a box of neutrals or just “some” gears one day and will need to be rebuilt or replaced. Hopefully you get one, they’re a must have car on my list. & also if so, join the 4th Gen. Camaro/Firebird Group on FB you’d probably like it. Good Luck.