440 roller cam conversion parts list.

You didn’t say what size roller cam, but the 915 heads are likely to become the bottleneck. I would spend the money on some aftermarket heads like Trick Flow 240s and then if you used a roller cam you wouldn’t be choking it off.
Haven’t made any decision on size. Figure if and when I decide to take the plunge I would talk to a cam guy and get one that suits my needs.