Trying to cut frame welded to connectors

[Doug1]

I need to cut the sub-frame loose from the DSE weld in connectors. I need a cutoff wheel that will reach deep enough to cut the top of the frame rail. THe floor is only about 1" away so I don't want to use a torch on it. A 7" cutoff wheel on a grinder hits the top but doesn't quite go through it.

I've got the side and top cut. Next time I'll bolt the subframe to the connectors rather then weld it. lol

Any ideas to cut through the rail without hitting the floor other than a cutoff wheel? If I can find a 9" wheel locally I can most likely get through it okay.