Cam install

So I ordered a new cam from Crower for the 400 and I had a single bolt cam and this one came in as a 3 bolt, but the new cam is abou 1/4 to 1/2 inch longer than the stock one? Before I send it back and call Crower Monday can anyone verify this is for sure wrong.
dam guy, there us a lot of diff. between 1/4 and a half inch !