Need help on centerlining my cam.

That would be the number one (cyl.) intake lifter. Yes you can degree with the heads off, using the lifter body. I wouldn't say that way is any more accurate. Just another way to do it. But for those folks who don't have thier heads off, or are just changing cams, it can be degree'd 'in' without having to pull the heads or off the lifter body. Centerline of the cam can be found using the valve retainer as a good base for dial indicator. Very important to insure the indicator is in plane with valve stem. As with the lifter body if you use that method. If checking (verifing) duration use @ .050 off the lifter body or .075 off of the valve retainer using 1.5 rocker, and .080 using 1.6 rockers. You have to allow for the rocker ratio if checking duration at the valve. I just prefer to 'see' what the engine is seeing. Good luck. Terry.