1991 Chevy K2500 6.2

I am reinstalling the transmission does anyone know the proper bolts size for the transmission to motor? Also trying to figure out the bolt size for flexplate to torque converter and for the starter to engine. All help will be greatly appreciated.

 

If they arec not 3/8" then they are metric,but the exact size escapes me ATM.

 

I believe the starter bolts are the same size as the transmission bolts because you can use them as extra long guide bolts aiding in getting the transmission lined up easier.and the flex plate bolts you should be able to get at your local parts store ask for GM flex plate bolts these have reduced heads for clearance and do use Locktite or thread locker or you may break the engine block.