Timing Cover Gaskets

The cam in my 360 is installed 4-5 degrees retarded. This weekend I hope to advance the cam several degrees. I plan to use this gasket set for the repair work:

1973 PLYMOUTH CUDA Fel-Pro TCS45284 Fel-Pro Timing Cover Gaskets | Summit Racing

Are there any tricks to getting a good, leak proof job? I'm especially wondering about the oil pan area. I believe there are 2 oil pan bolts that must come out, but the oil pan can stay in place, correct?

I'm hoping to leave the radiator in the car, but I suppose it could come out if it made the job easier. Any tips are appreciated.