HELP!!! 94 4.0 ohv lower intake manifold

[kmbtorch2008]

Ok so, i tore my motor apart to fix the blown head gaskets, working on putting it back together now, but come to find out i need a lower intake manifold, since mine is corroded at the coolant ports too badly to bolt back on. Does anybody know which ones will work, ive seen several on eBay, but they all say to check casting numbers for interchange...? how do i do that? if any one knows which ones will/will not work, please let me know!

Thanks,

-Kevin