Are you rebuilding the stock carb? If so, I know you already have the rebuild kit, but this would be a great time to do an amazing carb upgrade.
A junk yard ford motorcraft 2100 2 barrel with a 1.08 venturi size (stamped on the side) is a must in my opinion for the 258. They are very common. This carb was used for 20-30 years if I recall.
It takes a carb from a yard for around 20.00, rebuild kit for around 25.00? and the adapter plate from summit racing for 12.00.
Easy easy to rebuild, bolts right up, lots more power, in my opinion an all around better carb.
Lots and lots of writeups on this process on the internet if you are interested or just ask. I did it about 3 mo ago. Good luck!
79 CJ7 stock with 258 / MC2150 carb