I replaced the rear struts on my 99 Chevy Lumina 3.1. I purchased all OEM mounts, springs, and strut. The two rear strut mounts were differing model numbers (they were purchased separately several months ago online). The left rear mount was a discontinued (501-365) Delco w/metric and fasteners (nuts) were not included (thread specifications on studs 10mm x 1.25). I didn't know the thread difference nor their specs until after I attempted to complete the install. Long story shorter... in my attempt to smooth out the thread i damaged with a coarse thread flange nut part of a thread broke. I was only able to procure lock nuts locally for the strut mount. Is that good enough? I'd like to know which are viable options for me to pursue. Please add options I failed to consider. 

• use a 11mm x 1.25 to bypass the damaged threads near the top of the stud.
• Get a thread die and rethread the stud
• Place fasteners on the two strut mount studs temporarily until I can get around to fixing the damaged stud thread.
•