I do have a fuel pressure gauge on my fuel log between the carbs, but its only viewable with the hood up.
I will install a temporary flexible hose and run the gauge into the cab.
I will also pull the spark plugs and look for signs of running lean.
I will also recheck the timing - its pretty far advanced, but I have no problems around the hills by me, but around my house I can only get about 2-3 minutes of pure full throttle under high load.
the spark plugs Im running are rj8c
the engine is a 1958 261 with a high compression head.