88 Si Timing mark?

I have a quick question. When setting the timing for a 88 Si, do you use the TDC mark or the little white painted line mark? And also, would being one tooth off on one of the cams affect a car running rich? Please let me know if you know either one of these answers.

Drew

if u look where the transmission and the block connect, there is a little peep hole, get the #1 piston as close as u can to TDC w/ like a stick or somthing long and sterdy that can fit in the spark plug hole and llook in the peep hole, theres a little "T" mark or somthing that looks like that and to the exact right off the "T" which is on the flywheel there is a little pin type thing there and just line them up and u have TDC, about the cams, if the cam was one tooth off, it would run rough as fuck, and eventually bend a valve or somthin depending on which cam, when you do the timeing, if u have the cams where the should be, there is a little pin hole to line up, there is a hole on the cam it self and a hole on the last bracket to hold the cam down on the side where the cam gear is, just slide a skinny screwdriver in the hole when u have it lined up so u dont have to hold the cams when u slide the timeing belt on

We did the lining up the flywheel and found the point where the #1 piston is up. I got some new info today on my car running rich...a guy at Schucks AUto told me that it is probably the CAT or the o2 sensor (someone else told me that too). So i'm probably gonna replace both things and see how it runs. The question about timing is that one of the cams seems to be dead on, but the other one is maybe one tooth off...but the car doesn't seem to run rough at all. The flywheel is dead on too. Just wondering if that possible one tooth would affect anything...we couldn't get it to stay on with both cams. My dad and I used drill bits to hold the cams, but you have to have the exact right size or else the cams move a tiny bit, hence, the one tooth off maybe.

just replace the O2 sensor, cuz the cat has nuttin to do w/ it runnin rich, and if the cam moves a little then just use a socket wrench to hold it while u put on the timeing belt, just dont take the drill bit out untill u get the timeing belt on