Because the 67 and earlier cranks had the smaller register. I am not sure about 68 and 69 cranks , but my 273 had the smaller register in it. I found out the hard way, after building a 727 and getting a torque converter, then realizing the delema.
I thought I had a legitimate question why my 273 worked and perfacar said 273's must must be machined to work, meaning all 273's I must have used the wrong words or something because it set him off.
I appreciate your answer and I learned something new. We need more people with a helpful attitude like yours and less people flying off the handle just for asking a question.
perfacar I will be at Renegade this weekend for the first Summit race April 2 stop by and say hi. You will see that I am a decent guy and I am sure you are too. Here is my car you probably have seem it there. From your other posts it sounds like you have turned wrenches on the LemonTwister.