oldblue,
Don't know if you're trying to keep it original or not. I have a have a 261 with a rodchester and it ran poorly, I purchased a holley/webber from Tom Langdon and can not believe the difference it made.Starts right up, idles smoother, great throttle response.
You may want to look into this swap.
Langdons stovebolt.com

good luck


Tommy
59 apache 1/2t
261 short stepside