Hello can any one tell me the frame/ body type of the 1970 oldsmobile 98 convertible

 

GM B-body. <EDIT C-Body>
Formed steel, full perimeter type. Fully boxed midsections for verts.
Or are you concerned with cross-referencing with other similar GM cars?
A boxed can be used under a coupe but a coupe/sedan can not be used under a vert without boxing it in for structural reasons.
Not sure if 2 doors and 4 doors run the same wheelbase on a C body.

1969–70: 127.0 in (3,226 mm) wheelbase
1970: 225.2 overall length

 

The Olds Ninety Eight is a C-body. There's about a three inch difference in wheelbase between the B-body and the C-body.

Also, not all "GM" B-body frames are the same. An Impala frame is completely different from a Delta 88 frame in 1970. Totally different suspensions, for example.

 

I'm in Mopar mode at times when I think of land yachts. I digress.

 

I thought they were unibody.

 

HAHAHA! Yep. Further digression...