My Turn for a Cam question - 318 Build

Torque wise I don't think your gonna fine much difference down low could even go a could steps up before it drastically changes.
The 252 cam will give you a couple of inches of vacuum more and maybe a slight mpg advantage. When picking the cam for my 400 bronco i went with the 255deh cam even though I could of easily went with the 268 and picked up 30-50 hp. But I figured it was a truck and the 255deh would easily double the factory hp with what I was doing with it.
And figured I wasn't willing to sacrifice even 1 mpg for 30-50hp. In your situation there might be a 15-20hp difference but I doubt there would be much of an mpg difference I'd still go with the 256 but that is up to you.