thats all i used for out of the ip to the reg - then the return from the reg to the tank is -8
if it were a nos system i woulda went with -10 return to the tank but its not - my system works great
keep us posted on yours
don
ps - dont know what you mean by sooted up brazing a plug on the end of a pc of tubing does not change the i.d. its a easy way to attach braided hose to tubing coulda flared it but i dont like flares. the braze is good to 500 psi water pressure