another question...oil pump bolts..

I konw they are 3/8 x16 but how long should i get them? These are the (2) bolts that hold the pump to the rear main cap. I bought 2" long ones and they don't go all the way into the hole. I just want to make sure THere isn't an oil passage in that hole that will get pluged if i go to far in....or run it into a journal.

I bought grade 8 bolts from the hardware since the dealer said they couldn't get them.