Thinking I might throw together a very mild 383 for my 99 suburban. The 350 keeps having unusual misfires under heavy load only, and I'm leaning towards a slight head gasket leak between 3 and 5 or slightly burnt valve on #5.
Nothing fancy really, it will be a mostly stock type build as I'd...
Alright, so I rarely post anything in forums but this issue has us stumped.
99 suburban k1500 160,000 miles.
So I bought this truck about 2 years ago and it's always had some unusual runnability issues.
First it misfires if you lay into the throttle going up steep grades or floor it on the...