Welcome to the Forums! Glad you found us. Hope you'll share more questions and ideas with us. Pics are also a welcome sight. You're the first, that I know of from Saipan.

If you are up-grading your cranks with an expensive pair, then you will have to change spindle length. The Mfgr of the cranks will say which size to use. You will also need to know the BB Shell size --68, 70, 72mm.

However, if you are just replacing them with the same brand, then keep everything as is.