3 point hitch conversion

I have a D-17 Series IV and it has snap coupler.  I bought a 3 point from a 170 and am working on switching everything over.   I have all the old snap couple stuff removed and am working on putting the lift arms back on.   I marked the large splined shaft and the old arms in the middle when I removed them.   My question,  should I install the 3 point lift arms using the reference mark on the splined shaft with the middle of the left arms like the old snap couple lift arms or do I need to recognize a different orientation?   There is factory mark on the end of the splined shafts which I did not notice at first or how that oriented with the old lift arms vs. 3 point lift arms.    I have the arms cleaned and greased and can start them but it is not easy.   I have to block the other side when I drive on the arm.   Also,  I am only going to use the tractor to pull wagons and skid logs etc.,  maybe a brush hog.   Do I need to hook up the traction booster?    thanks for your thoughts.

Dr is right! There is nothing internal that connects to the splined shaft. Before you put those arms on, it woud be agood idea to replace the shaft seal on each side. Just a large o-ring Allis # 923922, slide shaft out one side and use a pic to get old oring out. clean and install new o-ring, then do same on other side. Literally 2 min of additional time!