Question for you: Are the bbl bosses all in the same position in relation to the Type 1 vs. Type 3 gas blocks? In other words, can you swap a Type 3 gas block on to a bbl that originally came with the Type 1 block? I'm assuming so from earlier comments you've made.
The reason I ask is I've been meaning to buy a spare bbl for my mini upper....not sure if the Type 1 gas blocks are even offered anymore. That means I'll have to switch over to the Type 3 (if that's the case)...but I'm not sure my current brake will clear the nub on the front side of the Type 3 gas block as it actually touches the Type 1 (the dumbass smith I had cut the bbl was supposed to cut it to 9"...which I marked on the bbl and he somehow managed to cut down to 8 5/16" since he didn't follow normal protocol and measure from the bolt face and instead measured from the bbl extension).
I know I'll have to buy a new gas tube (pretty sure the existing piston itself is fine and will work with a Type 3 block).