It’ll shift somewhat with cam chain stretch. Not much though. If it’s off by a tooth or more, the chain has most likely reached the end of its serviceable life and jumped the sprocket teeth or it wasn’t installed correctly in the first place. The proper indexing for the stock intake cam sprocket is #3 on top, #2 points to #3 on the stock exhaust cam sprocket, and #1 points straight down.
If you pull the center bolt and spring out of the chain tensioner (assuming you have the stock one), and then carefully remove the tensioner, you can then pull the tensioner to the end of it’s travel, counting the clicks until full extension. That will give you a pretty good indication of how much life the chain has left. Usually 2 clicks or less and the chain should be replaced.
If you did jump the chain, and the cam sprocket does not index correctly, you should probably either do a leak down test to verify your valve seats are in good shape, or remove the head to check for cylinder and combustion chamber damage.
Cylinder Works 434 bbk
Vertex forged piston
DRZ-E valve springs
DRZ base gasket & flywheel
Hotcams Stage 2 cams
Yoshimura full exhaust
YFZ450 FCR 39, Uni filter, no lid, 400EX intake
KFX450 reverse mod
Predator 500 clutch springs
YFZ450 front brake calipers
Outlaw 450 stainless front brake lines
Full Armadillo body armor