im with strgas, replace the entire place on rear of engine, at our workshop we no longer just replace the seal it self as the gasket behind the plate that seals up oil and water galleries tends to crack near the edges of one side towards the bottom and leaks from one of the 10mm bolt holes
if u are going to change the whole thing make sure u either have a few really sharp razor blade to get all the remaining gasket off the block, or a buffer gun of sum kind, new engine oil and coolant and some silicon to put on the edge of sum that sticks out under the plate
drain oil and coolant, rip the box out, drive plate, then rear main gasket seal plate, and u will find some water will go into the sump when it tavels down the back of the block, use compressed air with the sump plug out and in the gap at the back of the sump blow water out
once u scraped gasket all off block and put new one on
then reverse order and your done