Oil Pan 2001 Blazer 4.3 vortec
 

I own a 2001 Blazer 4x4 with a 4.3 vortec.I have the engine up ,and supported,all oil pan bolts removed.I can't get the pan to drop from the block.It seems to be held in the rear of the pan by something.The front of the pan is loose enough to wiggle up and down with a pry bar,I can see the pan move at the rear,but wont drop from the block.Has anybody had one of these oil pans off?Its an aluminum pan,it almost acts like there's some kind of alignment pins,or small guide pins,maybe that are froze not allowing the pan to drop from the block I have checked multiple times to make sure all bolts are removed ,even the bolts through the bell housing.Anybody have any experience with these?

there are two bolts under covers in the back bought the size of a half dollars

Thanks,but I already found them.