chassis Torquing problems in 65 mustangs

[netzaffe]

Hi, I have a 65 mustang that initially had a 6 cyl. I’m installing a 289 V8 and people are warning me about my chassis/body twisting or Torquing on me. Has any one ever ran into this type of issue, it’s not a hopped up engine or anything. Also is there is a reason to be concerned about this does any one have any sussgestions on what to do to prevent chassis Torquing and twisting?

Thanks