need help with leaky trans pan

You Guys are great! I have the same problem, I bought my 74 dart- 2 and 1/2 years ago. It came with leak (a904) that looked like a bad pan gasket. I put every kind of gasket on there; cheap rubber one from kragen, cork ones, hand cut my own extra think cork one, Mopar high tech one that was plastic with built in ruber rings I bought a new pan, After taking in on and off so many times the bolts got loose so I went with drilling lager ones, Then heili coils. Thats when I noticed hairline cracks from the bolt holes to the edge of the tranny in two spots. Did I make those? Not sure but they leak. I could have that problem where the leak is comming from the top somewhere and collects on the pan/tranny case meeting point. But now I have cracks at the bolts and maybe a leak up above. I spend about $10 bucks a month on tranny fluid and mix it in with Summits stop slip as it is thick and leaks slower. So I understand the kid throwing in the towel. It is very hard to keep putting you car up on jack stands week after week thinking no way it will leak after this but then it does. The great thing about this is- Ma built a great tranny that will run almost two quarts down! Now please help answer my new thread about a904 swap from slant 6 to a 318 do I need anything to make this work?