There's not much metal there to screw into, do they come out pretty easy? I did a forum search and there's a lot of info on putting them in but not removing them.
I have one in pieces that I got from Modified Mark a few years ago. Suppose I should dismantle a 3400 to get the rest of what it needs and get it running.
Those Sunbelt kits were made in Jasper ,Mo. just a few miles from me. I sold Gregg the one he has and I've used a couple of 3700 and 3400 kits, the seem to work good. Too bad they're not still in business.