Cub Cadet 1042 w/18hp courage

[The kid]

I have a Cub 1042i which is running great but some how the two exhaust bolts can completely out. I have search the net for what size these bolts are and come up empty. It's a Kohler Courage 18 SV540S-0020. Any help would be appreciated.

 

[radios1]

how about Part #710-0599 1/4"-20 x 1/2" hex head cap screws with lock washers?.