is a 1970 monte carlo frame the same as a 1970 chevelle

Hi Robert,
I don't think so as even though the wheelbase I believe is the same at 112" I think that you'll find that the Monte frame is longer in front of the steering box due to the extended front end. My parts books call out for # 3960733 as Chevelle 2-door hardtop and 3960735 as 2-door convertible and 3990562 for Monte Carlo. Maybe some Monte Carlo guys will chime in here and shed more light on this.
Chris

No they are not the same.

nope

No, the front frame horns are longer than that of a Chevelle.