[Mike Wessinger]

While I have had my old truck for years (65 C10 with 230), I have only recently began getting serious about learning to do the mechanical bits myself. With that little disclaimer, I can offer that I was having a similar "not starting" issue recently. I thought it may have been the battery, so I stopped by my mechanic's shop for a new one. I stopped at a gas station a few miles down the road, and even with a new battery it took a few tries to get it to start.

My "fix" was to replace both battery cables with brand new, heavier battery cables. I also used an existing empty threaded bolt hole near the dipstick tube to add a ground strap from the block to the frame. That has been almost two months ago and I have not had a single repeat of the "not" starting issue.

May or may not be what your truck needs, but just throwing it out there as a possibility