Whatt to do?

I just picked up a numbers matching numbers 1969 Dart GTS with a 340/4sp. The car has 55K originals miles and is a true survivor. F7 with black vinyl roof and interior with the black bumble bee stripe. It looks beautiful. But I have a 950hp 571ci BBC just sitting in my garage I want to swap out because the 340 is so wimpy. Do you guys/gals think that is a good idea?