You can get the main cap at any salvage yard or maybe a local shop has one. But I do believe that the main caps are machined with the block. So there could be a slight difference in the fit of the cap?

 

I found out I'll still be able to use the cap so all I will have to buy is just a new pump. Should've changed it the first time around. The torque for the oil pump is 30 or 35 ft lbs? I've heard both. First time I torqued it to 35ft lbs, so this time I'll go 30 instead.