One of the fastest ways that I found to fiure out if it a 3.98 stroke is to stick an pencil down the spark plug hole and measure the distance of travel.But use a new pencil so not to lose it in the cyl!
STan
And yes the 410 is a stoke 390 bore with a 428 crank.YOu can look at the crank and find the numbers on it it need to read atleast a 1U that is the standard 428 or 1UA 428CJ,1UAB or 1Ub for the 428 SCJ.