need oil pan info

[scavengerdog]

i've got a medium-truck 366 in my 70 gmc 3500. it's got a rusted-out 8 qt oil pan & i'm looking for a new one or a like-new used one. i would put in a 4 qt if that's all i can find but i can't remember what fits for sure. it seems like the pan off the original 402 should fit if i change the oil pump pickup? it needs a clutch at the same time and i'm going to have to "borrow" a space to do the work (pull the engine) so i really don't want to have the wrong part on hand. any good info would be appreciated.