Frame questions (interchange)

I have a 60 Biscayne that has had the floors cut out of it and a truck frame grafted to the stock frame about at the firewall. I also got a 61 Impala parts car for the frame but it has some rust issues so I am hunting for another. I've found a 61 Skylark and a 62 Impala 4 door both are in good shape frame wise but will either of these fit my car.
I'm looking for basic size here as the car needs complete floors anyway so changing a body mount here and there won't be a big deal.
For the price I'm finding bare frames for I figure I could pick up one of these and make back some of my money parting the rest of the car out.
Thanks for the help.

 

62 impala frame is close, but won't bolt on...we just went thru this discussion a week or two ago here.

Buick used a different ch***is than chevy, although parts of the body were the same. The Special was a small unibody car,

 

I saw that thread but didn't know if the 4 door frames were different than the 2 door

 

Aside from possibly a mount or two the 2 door and 4 door are the same.

 

Thank you.