Troubleshooting Strange Noise

[82K15]

Hey guys, this is my first time posting. I’ve got an ‘82 K10 with an 88+ 350. Just did a lot of freshening up after blowing a headgasket. New FloTek aluminum heads, new intake, accessories, the works, but I’ve got a strange noise happening now. It’s a loud, intermittent bang. Sounds almost like when the torque converter bolts work their way loose, but I’ve already checked that off. I just wonder if it could be running too rich and putting unburnt fuel into the exhaust, then detonating. I know it idles high, I haven’t really been able to dig into it much further due to weather. I’ll attach a video if I’m able, thanks and God Bless.

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[mxer147]

Probably an exhaust leak

 

[ali_c20]

Welcome from Austria.
I would do the following: Adjust timing. Adjust idle. Check for exhaust leaks. An engine stethoscope is very good for finding engine noises.

 

[Radiohead]

An engine stethoscope is very good for finding engine noises.

In a pinch, a couple feet (.7 meters) of vacuum line makes a good hearing instrument for exhaust or other leaks, while a long screwdriver or prybar makes a reasonable stethoscope. I know this because I'm cheap and it works for me.