I'm planning on looking at a 63 FLH frame.
Are there any points on the it that I should for cracks?

 

H-D p/n 47261-68 ( V-twin # 51-0506) was a retro fit gusset to strengthen frames from 58-68 at the left side near swingarm.
Presumably this is a weak point

 

What 88 said, that is the usual problem spot. Having bought a '59 frame last year, here to tell you they can look straight until they hit the table and a laser tells the story. If building an original type bike, make sure all the tabs and tank mounts are present. Good luck.

 

Thanks for the quick replies! Great info!