question about oil filter adapter

I have a 1992 Cherokee with a 4.0 liter engine. The engine has over 200,000 miles on it and recently developed a bad rod knock so I decided to replace it with a remanufactured. The problem i am having is the oil filter adapter. The new engine is threaded so the oil filter attaches straight to the engine block with out the adapter. My question is, has anybody installed an oil filter this way? The mounting surface of the block is tilted slightly downward and it would appear there would be little if any clearance between the filter and body of the jeep. Also, the new engine came without the little pin that is installed at the 12'oclock position that holds the oil filter adapter in place while torqueing it. If I have to install the adapter, can I install it with out the pin or do I need to try and find a new one? Thanks

I don't think the filter will fit if threaded directly to the block.
http://madxj.com/MADXJ/technical/technicalfiles/ARoilFilterConversion/OilFilterConversion.htm
You might want to check out that page, he's got a lot of pictures of the "L" adapter taken apart. Is is possible to unthread the piece in the block now and thread in the L adapter from the old motor?