Yes, SRT6 conversions with MT have been done. But there are some problems. The transmission is designed for 400 Nm. The SRT6 engine will produce 460 Nm, or more. The clutch itself is not the problem. There are reinforced clutches available on the market. Main problem is the dual mass flywheel. There's no reinforced version available. So, it works in general, but livetime is defintely limited. We have a 5.0 MT test car over here in germany. The dual mass flywheel was ready for the scrap heap after about 12 K miles.

Regards