S4/S5 CAS timing position
 

Hello everybody I have a 91 turbo fc running a microtech and when I put timing lock to time the engine with a timing gun I lined up the leading mark to the timing cover, and the CAS is almost if not at the middle position, however my mechanic said thats way too advanced and i could blow up the engine... can this be true? i went over to check the timing again and the 5atdc mark is exactly lined up with the timing cover pin... is my mechanic right or am I doing it the right way? He says the CAS should be almost all the way retarded (rotating it counterclockwise)....
The photo is how my cas is positioned right now
https://cimg4.ibsrv.net/gimg/www.rx7...d1a78f7ed2.jpg

The CAS is usually about 70% to the right once timed to the yellow mark.