Hi, I was always thinking a 440 or 400 swap into my 73 cuda, but now wondering if a newer hemi would be a better choice, would like to see around 600-700hp, automatic transmission, what is the the best bang for my buck? Do I go used with all the parts? (Wiring, pedal) I saw a hellcat engine/ trans for 12,000, good buy? 8,000 miles,, . is one of the newer trannies a good bet? Or will a old 727 work out? Are there mount kits available? Or do I go with a new crate unit?