I purchased a 78 280 2+2 from a guy in NJ, I drove it 2.5 hours home and it ran fine but it had major rust issues. I also have a 280 (SAT FOR YEARS) that has a half decent body with little rust, I removed just the engine and trans from the 2+2, nothing else. I have a set of SU carbs that I purchased from a member online here I removed all the emissions crap from the motor and put the SU's on, the car ran fine for 15-20 minutes we shut it off for 30 minutes to clean up. We went to start it and a nasty rapping sound is now apparent. There is black tar like #$@% all over the valves and one is sticking now. This will be the 3rd motor that this has happened to, different valves sticking but still the same problem with all 3. HELP!!!!!!!!!! lol.