1-1/2 inch fuel opening on blazer tank.

[englands 71]

I bought a blazer tank from Southern Ky Classics and so far its been a "youre on you're own kinda deal. First of all the tank has a 1-1/2 inch fuel opening . Now what the crap is that all about ? How the heck do you get fuel not to back up and burp through such a small hole ? No instructions - youre just on your own. I know there is a crap load of threads on moving tanks , believe me I've seen them all . Is there anyone on here that bought this tank and what did you do as far as going from a 1-1/2 inch opening from the tank to a 2 inch opening on your s-10 filler neck ? Can they stretch a 1-1/2 pipe to a 2 inch ?