Hi there everyone. I have been enjoying my truck after getting all the ignition and timing sorted, no leaks since I installed the new brass fuel inlet fitting and it starts every time now with no fuss (it's faster to fire up than my 2007 Honda...;-). The only issue is that I am concerned that I believe it is running lean. When driving, it seems to pull pretty good and responds to the throttle well, but I have no reference point for what a 235 should feel like. It's a 235 from 1954 with a Rochester B.
To test the jetting, I drove it for 25 miles on the freeway at about 50mph and when I pulled the plugs, they were bone white at the porcelain (see attached). The strange thing is that the jet it came with was stamped 52, but when I compared it to the new 56 jet I have, the 52 looked much larger, but did not have the eased edges on the 56 (it looks like a straight drilled hole - see pic). I am guessing that someone drilled out the 52 to try and make it work in the 235. From what I have found, the factory jet size should be a 58, and I wanted to know is... - if it is running lean with a jet that looks much bigger than the 56 I have, would I need to go bigger than the stock 58, or do I need to be looking for something else that could be making it run lean? Does the chamfered/eased edge of the jet opening make it mix fuel better? Maybe i have a vacuum leak? I am getting right at 21hg at the port that the wiper vacuum hose connects to on the manifold.