Worth it to build my 273?

I am building my 273 to 235 Hp + specs but I am the 2nd owner of an original car and wanted to keep the original 273 engine. I am building the 904 to perform and adding an 8 1/4 3:21 shur grip differential with LBP for the added Hp. I will be road tripping my car a lot when finished but may time it one time for kicks.
DR