does it matter if its on echaust stroke or compression stroke to time an engine...

 

you want the motor to be on "tdc". that is top dead center of number 1 cylinder. you want everything to be on tdc. tdc is on the compression stroke on #1. "b", and "h" motors are interfernece motors. in other words if you don't get it in time you may bend valves. "d" motors are not like this and won't bend valves. any way you still want everything to be on tdc. they give you the marks on the crank and cam to put it on tdc.