Bolt / thread size used on PTS TCS 9x11 billet torque converter?

[1KWIKSIX]

I'm about to install my used PTS / TCS 9x11 billet torque converter & have discovered that the 10mm x 1.5 bolts do not fit?
Wondering if maybe they have been re-tapped to a different size / thread?

Can anyone recall what size bolt is used?
Any other tricks or modifications req'd to mount this converter.

Thanks for your help.

dave