438 build camshaft

The bigger one (XE274) would be the smallest I'd consider. Big cubes need duration. With 438 cubes and a XE274 you won't even need much stall. 2500 will probably be enough.

I used a XE274 cam in my 360 at first and it was pretty torquey and pulled hard to 6000 rpm. In your 438 I wouldn't expect it to pull much past 5,200~5.400 rpm. Just not enough duration. Haven't used a Hughes cam but I'm getting ready too as I have one to go in a 408 I'm building.