[1FUN64]

Just went through the oil pan research deal and came up with some good info. I need to start a thread about this but here is the quick and dirty.

Go to GMpartsdirect.com, put the following part numbers in the search and it will show pictures with dimensions and at the bottom it shows all the part numbers of the items to work with the pan, windage tray, pickup tube, etc... Also has application information for what they originally came on if you want to hit up the salvage yards.

12628771
12631828
12640748
12581209 Front sump (not what you are looking for) maybe what you have.
19212593 "swap kit" 8" rear sump, Summit.com will show all dimensions on this one.
302-2 Holley replacement pan, Summit for these dimensions also.
302-1 Holley also, Holley.com for these dimensions.

You can also search these part numbers on ebay for some products also. GMpartsdirect has some good pricing but shipping and handling is kind of expensive.

Good luck with the swap.