Spec on a 98 big block is 6' (dont the little circle for degree's) at 1500, 6' at 200 jumps to like 12' at 4500, peeks at 17 around 7000 then starts to retard toward real high rpm.
the 6' spec says plus or minus 1.5', and as polaris1010 mentioned, you need to run a dial indicator in the mag side cylinder to ensure the timing marks you are looking at with a timing light are spot on. 6' before is 0.0092" (hundred thousands of an inch) before top dead center.
The reason I know all this is I just rebuilt my motor and installed a new stator, I have it all buttoned up, runs awesome, but I realised I never put a timing light on it, so I looked up all these spec's, and guess what I get to do tonight after work...
good thing is I have put maybe a whole mile on it since I got it running.
And by the way, the specs were the same for the 700 also
98 Polaris XC600 (M10 suspension, Boyesen reeds, SLP clutch kit, SLP can)
95 Jag 440 (daughters sled)
"Speed is expensive, How fast do you want to go?"
"You must be fast, cause when I passed you I was Haulin @$$!"