replacing leaf spring shackle bolts?

[northeimcustom]

I am just installing some drop shackles and I had to cut two bolts off. Stock i am assuming, They appear to be 5 &1/2 inches long 1/2" ish, grade 8. However, the brand new grade 8s I can find locally are 5" (which is fine for length) 1/2" diameter grade 8s. The shaft of the new bolts seem to be smaller in diameter than the ones I cut out. So there is a fuzz of play?

What do I do??