I'm Torn

I have the original teen in my 70 Swinger. It needs to come out for a re-seal but if I could find the right engine...... well you know.
Exactly haha! They guy i'm talking to on here who is local to me is working some things out. If it doesn't work, i've got time. The 318 runs ok and gets me down the road. I just want something more! 360 even. My dad has a 65 GTO with a 456 stroker. I think i could beat him with the power to vehicle weight ration!! hahaha. Not building a drag car though, just a nice cruiser that will GO when i want it to. Rear suspension and cleanup is this coming Winter's project, while cleaning up a new engine if acquired.