Since the thread welds failed I had to cut the head off of my bolt to get the seats out. Or else it just kept spinning and never became loose.

What should i do? Weld it back on? I’m trying to install new racing seats if that changes anything and I don’t know how I feel about driving with 3 bolts instead of all 4.

 

I'd use nutsert or rivnet to replace them. Not sure what size you need.

https://www.fastenal.com/products/details/0125658

Threaded Insert Dimensions (Nutsert/Rivnut) | Anzor Australia, Brisbane

 

first you need to treat the rust.