Not being a SA here, but sounds like you need a service manual. It will answer all the factual dimensions you need to measure, build and repair the motor. Although I am sure someone will chime in. But even then, you should have one, for future reference. Parts manual helps too.I recently acquired a 61 fl motor,the top end is off as well as the front cylinder my question is how can you tell if it has stroker or not without splitting the cases. First engine build and would appreciate the help.
I must have been asleep when I read that. My brain saw 61, so I thought he was asking about an el.Since he was asking about a 1961 FL I only gave him a number for 74 CI as 61 CI engines ended in '52 and the crank wont fit the later cases. 61 CI engines also have a smaller bore, 3-5/16 as opposed to the 3-7/16 of a 74 CI.
If someone truly wanted to though they could build a 61 CI engine out of any pan with a little machine work and small bore cylinders. Then you would be making a dog into a lazy dog!
Did you have to use a 61 cam?I have built several 68CI engines using 61 flywheels and 74 barrels at 3.5 inch bore. They rev nicely and pull hard as well as being very smooth running. I like them well enough that I plan to build one as my next knuckle project, a '40s TT replica.
H-D themselves used such an engine in the '40s for some of their military projects.