The Rochester B, BC, BV usually (maybe 90%) have a warping problem. It's caused by material decomposition (sometimes called zinc creep), age and design. Attempts to correct the warp has had some short term successes (lasts maybe 5 years). The direct replacement is the Carter YF 2100S, if you can find one, is the preferred choice (use an Ethanol resistant rebuild kit). There are other replacement carburetor options but the discussions can become quite long.
If you use your truck as a farm truck, as long as it will start and run, it doesn't matter. If you use your truck infrequently (drive on Sundays, car show or parade), it may be okay. If you use your truck as a driver, find a better carburetor and place the Rochester on the shelf.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
