12-21-2022 - TODAY A CUSTOMER WITH A MDJF BLOCK CAME AND COMPARED HIS BLOCK SIDE BY SIDE TO MY BLOCK AND WE CAME TO THE CONCLUSION THAT THESE ARE THE SAME BLOCKS. (Minus a plug here and there) And my RDJF block has on one end mounting holes tapped for a water pump. RDJF ENGINE BLOCK 110-1699 ONAN 4 CYLINDER ENGINE BLOCK CASTING NUMBER ON BLOCK IS 170-2722 CYLINDER BORE IS 3.5" BLOCK IS 21.375" OVERALL LENGTH ATTENTION PLEASE: These 110-1699 block got wet while in storage before I purchased them. I have cleaned off some surface rust. There may be a small amount of pitting that may take a bit more work to get to 100%. A wire wheel on an angle grinder was used. I have oiled the blocks down after my cleaning. Please ask for more details if necessary. NOS new old stock Other countries must contact me for a postage quote. I am not an expert concerning much of what I sell. Please send Onan part numbers when inquiring about certain parts or the Onan model and spec #. Please look at my other items in my STORE and add me to your favorites list. Click on See all Categories for additional products. .... Cheers, Mike Powered by Turbo Lister The free listing tool. List your items fast and easy and manage your active items. 11-3-21