I have a gm crate 502 with an 8 qt oil pan, thats what i was told, i just changed the oil and i put 9 qts because of filter and the mark still low, any suggestions would be appreciated.

Thats what it should be considering all the engines i have seen and changed oil in. If it is a new motor make sure the dip stick was mounted properly first obviously. Other than that there shouldnt be more than 9qts to fill a 502 with stock pan. Are you running a oil cooler other than a rear mount, where the lines will be much longer?

If the motor has a stock 8 qt pan and a 1 qt filter,i would stick with the 9 qts. Sure,the oil cooler and lines hold some but you really aren't getting the oil out of them unless you have removed them and drained them. If your dipstick is wrong and you were to put too much oil in it would windage around the crank and cause you more problems than only having the 9 qts would,make a little reference mark on the stick and when checking oil read it instead of the stock marks. On the common sense side of things,when you check your oil you should always repeat the same routine,i check mine on trailer after it sits over night (with motor fairly level). You wouldn't want to run your motor briefly (oil is still cold and thick) and then check it (it would show low because cold,thick oil is clinging to crank,rods,cam etc) because it would appear low. You also wouldn't want to check it sitting in the water if motor is on a angle unless you keep your boat in the water all the time(then you would want to change your oil like you did, put the 9 qts in,put boat in water,let it sit for a while and check it and make a reference mark). I hope this helps a little,Smitty