I know some of this was already said in recent posts, but I wanted to consolidate info on the adjustable bowls for new users, so here it is again:
If anyone thinks they’re getting legitimate leaks from the panhead or shovelhead, you can test it by covering the top of the bowl completely with your thumb or hand and trying to draw through it normally.
For me that shows no air leak, but if you do notice one and it’s not coming from something you set up incorrectly*, and if resin doesn’t quickly fill any tiny gap that’s there, you can use o-rings.
I don’t think anyone here has had to use o-rings with the final version of these bowls, but in an earlier test version a little airflow was possible for some people due to a slightly larger gap between the post and the hole in the bowl.
If you think you need to go that route, I believe there’s info on which o-rings worked well earlier in the thread, but my guess is most people seeing a difference in vapor density between bowls are getting it from the difference in height of the bowl, and we should be able to adjust for that by raising the temp of the head.
Anyone worrying about panhead vs shovelhead, other than a little mass like
@steama said, it’s just a cosmetic difference. I have one of each and I’m happy with both (although I do want to try glass).
* If you’re not sure your panhead or shovelhead bowl is set up correctly, this video should help: