Brake Line Distribution block port sizes are different

Thanks for your replies.
On Valiant .org& Slant Six.org there is pretty detailed info on how to convert to dual with the original distribution block -even says to check for restrictions. 1 line to the front distribution block,plug the rear port & run 1 line from front pot of master cylinder directly to the rear. When I finish this I will update with any issues or problems i came across . I did purchase a new rear tee fitting & those inlet ports are MUCH larger than the ones on my original- not sure why .