I was at the body shop today to see my car get some color (greta news--I should have it back in a couple of weeks)!

My concern stems form the fact that when they started it up to move it formt he prep area ot the paint booth, the exhaust was popping (backfiring) a little bit...

What could cause this (it was not backfiring when I brought it to the shop in the beginning of November?

missing some info but assuming its the 383--probably needle and seat on carb from setting check plugs --might be dist but dont know what u got

If it sat for five months and didn't make any noise I'd be more worried....and I'd be checking the odometer.

I'd guess they started it a few times to move it then shut it right back off. Probably a gas-fouled plug, which should clear up when you drive it and get it up to temp.

Firing up cars in a paint shop.....hmm thats not good practice for a starter
Yep I would check the odometer...u did take a reading /cell pic?
And checked the rear tyres...that they are not now attached to the inner gaurds.

Odometer is right...107 when I dropped it off, 107 and some change yesterday!

Tires don't seem any worse for wear than they were when I dropped it off...

Car was outside when it was started, backed up, then pulled into the bay with the paint booth...The shop has multiple bays (all accessible from the outside), and was moved around the property slightly, as needed...

Hopefully just a fouled plug...I'd hate to get the thing back and have it run like crap all the way home once it is done at the body shop!

Be sure to check it out prior to driving any distance, as I have had valves begin to sieze in the guides, when the car was started multiple times (for a short time, to move) and not allowed to circulate the oil (or be brought up to normal op temps). Strangely enough, I had this issue while it was at the body shop as well, and was being moved around to the various repair stations. I had to pull the heads and install some valves and guides to repair. I hope this isn't your issue, but I would be very concerned if your engine is fairly "fresh", with close tolerances. Just be sure, to prevent any possible progressive damages. The simplest check would be to perform a compression test prior to driving - hopefully everything is OK, and just as others have posted (possible fouled plug, etc.).

Vacuum leak

Most likely of all is dust, espec that long a time in a paint shop
Good oil change, set plugs, clean HT dizy etc, grease the nipples, fresh water
and I will lay odds its good to go.
What is suprising and is very common under these circumstances is the battery dies.

Raw gas dumping into Exhaust probably from a miss firing plug then ignites and pops in the exhaust. Sometimes an Exhaust leak before the mufflers (Blown Collector Gasket) does the same thing when you let your foot off the gas. The incoming Air Super heats and Ignites the unburnt fuel in the pipes when the throttle is suddenly closed but this usually happens when the Engine has reached temperature - great way to blowup mufflers ;o)

Engines are so inefficient at start up I can't even stress enough.
My cousins LS motor runs fat on a fat tune and for the first couple of minutes until the cyl. temps get hot enough some fuel will get past ignition and pop in the heating exhaust. Totally normal. Probably happened all along just didn't realize it until you were in a building where stuff sounds different.

Battery is dead...they had to put a jumper box on it to start it...

got good paint, though...striping it this weekend, then re-assembly...

Ron, speaking of blowing mufflers, did you ever cruise town with your folks car, coast down a hill, turn off the ignition and then turn it on again?

What color is that? Kinda looks like Electron blue and a little darker than Viper blue... Is it an original Camaro color or different? Haven't seen a stock 67-8 color that shade before, looks good, closest I could get to a dark blue for mine was viper blue or the electron blue from newer cars, looks good!

GM had two names for it--on the corvette, it was called "Lemans Blue (2004),
and on other models, it was Luxo Blue (2004)

Getting GM white diamond Z-28 stripes this weekend)...