I just finished a 416 CI that is basically stock with exception of a Crane 343901. I'm looking for more low end grunt for towing and that is what crane tech recommended. That's with around 10:1 compression and 4.10 gears, 435NP, 4 speed.

 

are you set on keeping the stock springs? If you are willing to change springs then you have more options of cams with lifts over .500".
Like Wulff said, new lifters are REQUIRED with a new cam. Might as well throw in some springs?

Also the D2 heads CC between 68-72cc (associated with the chamber shape) usually, although like many things they can fall outside these parameters. They are one of the smallest chamber sizes and have pretty good porting potential.

 

I have to add this information: Alway's use new lifters with any cam replacement. No exceptions. I also can not stress this enough, use an oil supplement like "trick flow" from summit to break the new cam and lifters in. If you do not, I can almost guarantee you will be tearing the top end back down and replacing both the cam and lifters again. It's happened to me, and several others that I know. We thought synthetic oil woud be OK. GRRR I could explain why, but I'm tired, and gatta get up early

 

Oh gee, I can't believe anyone would use synthetics for a break in

I'm going to dump ZDDP in during the break in, and half a bottle every oil change from then on. After the break in, we'll likely run Rotella 15w40 Synthetic.