1987 Z-28 305 cid / 5.0Ltr 4 bbl Rochester carb. 7,000 miles on new crate engine. Sometimes when I start cold engine, I get a popping sound for a few seconds and then it goes away. Sounds like exhaust popping in engine compartment, not below in exhaust pipes. There is no cylinder missing, no trouble codes. It seems to happen more if I don't start car for a week or so. I'm not sure if a lifter is going bad or if it's something's hanging up in the pollution control system. I don't hear rocker arm clicking that you would hear if a lifter was going bad. Does anyone have any ideas? Thank you.

 

Wrong forum... "LT1 Based Engine Tech" is for the 93-97 LT1 engine. I'll move your thread to "General 67-02 F-Body Tech", where you will have a better chance of getting a response.

 

As you can see, unfortunately not a lot of 3rd Gen owners on the site any more. Mostly LT1 4th Gen owners.