".......so i cant slam the pedal to the floor even in 1st gear?....."

Kid it's your car and you can do anything you want with it.

Honestly I thing most of the old timers (geezers) myself included found out how weak thing were by going out and breaking them. Now here's the problem as I see it from this and previous posts. You have a 57 Chevy 4 dr (either a hard top or sedan.. you've listed it as both) that's pretty original with a questionable frame, stock drive train (which is likely pretty tired unless it's been gone thru sometime in it's life) brakes that were somewhat marginal even when they were new, and needs a paint job.

Now you want to drive it like it's a real hot-rod, sorry but you can't have it both ways. You can either drive the car like it was intended and enjoy it for what it is, or you can take it out and break it and up-grade it as needed (originality out the window).

As far as detergent or non-detergent oil, unless the car has been parked for the last 30 years, chances are that it's been run with detergent oil since the 60's.and there's no sense going back to an inferior oil at this point.

Finally, if you think your engine needs restore what it likely really needs is to be pulled out and rebuilt.