Hey my 305 in my Z is leaking badly. The engine was removed and rebuilt by me and my dad( he has been doing this for over 20 years). It isnt the rears seal becuause there is no oil near that area. The oil is coming from the last two oil pan bolts. I tried tightening them but it did not work and the pan isnt warped because it isnt leaking from the top only the bolt heads have oild on them. What is wrong? how do i fix it?

 

If you're absolutely certain it's not the rear seal, you may have pinched or ripped the oil pan gasket. Or there may be a piece of the old gasket stuck to the pan rail.