I ran into a guy selling a '95 with a new LT1 (about 5k on the new engine) but when I took a test drive, it backfired at high RPM: I took it on the service drive and lit it up. It took off nice but when I backed off the gas pedal, it backfired. Any ideas what it could be?
My first thought would be valve springs or a bent pushrod, but it's a new engine and would hope they are still good. Maybe it's opti-spark or the plug wires arcing?
Any thoughts would be appreciated. DM