B&M Auto Transmission Flex Plate for 360

Only difference is the converter bolt spacing. The 10239 has the wider 11" spacing used on some of the later Magnum engines. The 10236 is dual drilled but only 5/16 bolts for the 11" spacing converter bolts. It does have both 5/16 & 7/16 for the 10" spacing.

And I am fairly certain that Part #10235 is for the 1 year only 1973 external balanced 340. I don't care what it says online. How do I know this? Cause I have one sitting in my shop that I just pulled off a 1973 340 external balance engine a couple days ago.