It also looks like Delta only offers widebody service JFK-LAX on a very select few flights (e.g., one daily I think). The other flights are on 757s or 737s which would have a standard domestic first class configuration with 38" of pitch (however these seats would actually be noticeably wider than either DL's 767 widebody business class seats, or AA's J seats).

To compare AA to DL J seats, the primary difference is an extra 10" of legroom on Delta. Now, the 50" on AA isn't really skimpy, particularly for a daytime flight, so dougny, I might gather that at 6'2" 220# you feel "snug" probably more because of the narrow seat widths than lack of legroom? The only remedy for that is doing a narrowbody transcon on DL, but then you sacrifice all the legroom. (Come to think of it, if UA's p.s. J is 2x2 config which I'm sure it is, seat width is probably much more reasonable)

Or, look into CO from EWR and pick one of their 767 flights which offer 2x1x2 seating in First, so wide seats, and also plenty of legroom (55" pitch), or a "752" flight on an internationally configured 757 with essentially the same seats as the 767. There are usually a couple of these a day. And the service on CO is great.