I have a 94 B4000 4.0 OHV. On my way home from work tonight it started over heating and lost all the coolant my drive is about 10 miles and I was about 1/2 a mile from home. I got home and started tearing into. I first put a pressure tester on the coolant system and it held no pressure and I could hear a hissing sound behind ac compressor. I took off the compressor and p.s. pump and it appears either the lower intake or headgasket is leaking. I haven’t had any issues with it leaking before. What is the process for replacing the lower intake gaskets? TIA