You know you can build a 904 to take some serious horsepower. I know a few of them running 10's and one is running in the mid 9's twocents
Just saying you can build what you have and keep all your other components the same.

Gus beer

64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60