Rear Spring help

[stevewhitmore]

Hey Guys,
Trying to replace and put lowering coil springs on the rear of my 69 and cannot get the top bolts broke loose up inside the springs after days of soaking with penetrating oil and using a breaker bar to no avail and busted knuckles.
Any idea's, I am sure someone else has had the same problem.
Does this bolt screw into a weld nut or a regular nut? (that you can't get to)
Appreciate any help or thoughts

My only thought is to cut the springs up high with a cut off wheel and then try to cut the bolt head off?

Thanks