The exhaust valve is still open at TDC and the intake valve starts opening almost halfway down..
You know...back in the 80's...I had a 460 block on a stand in my bedroom...eventually I moved it to the little garage when I was done admiring it and went about filling it up with components...
Once I had the rotating assy. in the block and was about to link up the cam and crank...I decided to set the crank gear to the 'Factory' position...(8 degrees retarded..) just to see what effect it would have on the cam timing...
I was surprised at how far the piston traveled downward before the exhaust valve shut completely...(!!!)...HM !! and then the intake valve was opening just as the exhaust valve was closing up...(overlap)...
So then it dawned on me...in order to meet emissions tomfoolery...the manufacturers retarded the timing to accomplish at least two goals...
One...the size of the engine...as far as swept volume in each cylinder...is reduced and they can use a larger engine that they have... instead of having to invent a smaller engine immediately...( the 'Romeo' engines were probably on the drawing board but nowhere near ready for production...)
Two...the EGR system has less to do to dilute the intake charge and reduce combustion temperatures...thus cutting back on the potential generation of NOX...because some exhaust gas is pulled back into the cylinder...or never left until the cam timing was durn good and ready...
This is probably the reason that the 400's and 351 M's had gotten such a bad reputation as a 'doggy' engine...retarded cam timing...
I yanked that crank gear off as fast as I could and put it back on in the 'right' position...and then turned it over...
Ahh....much better...