Hughes 27-30 and B&M 10239 will not line up.

have you tried to slide the converter in to the trans? how about a pic of the other side so we can see the hub. they are much smaller than a 727... take a quick measure of the drive hub diameter. you will have a good combo when you get all the bugs worked out! i love 904's i run them behind all my small blocks in cars. and that B&M piece is good quality i have currently installed 3 of them in projects with the 360/904 combo. never had any problems! good luck with the build