[ossiblue]

If your fuel pressures now are in spec, it's quite likely the bucking problem is vacuum leak related, especially if it tends to get worse as the engine warms. Air/vacuum leaks lean out the mixture and as the engine warms, the fuel pressure regulator is also leaning out the mixture making a lean condition even worse. Your pop-off valve is a likely suspect since it was a problem before. I'd suggest you totally remove and re-glue the valve in place with a good epoxy rather than use a silicone sealant, but that's just me. If that doesn't fix the problem, you'll need to do some investigating of the entire intake system and vacuum system to locate possible air leaks--there are dozens of possible suspects--but at least this has been done by many, many of us and there are ample threads available for help.

Keep us up to date.