That power beyond block only works with a side console 4020. Both old and new 4020 are closed center so you must use a closed center valve for whatever else you want to use. Otherwise the hydraulic systems have very little in common, most everything was changed. I have a web page about early 4020 with some late 4020 tests http://www.geraldj.networkiowa.com/4020si.htm

For power beyond on the early 4020 you replace that elbow by the brake pedals (feeds the rock shaft) with a T and thats power. The return should be to the transmission oil filter cover, not the transmission case. Deere sells a tapped cover first used on the 2640 that fits. I drilled and tapped my filter cover and its working fine.

Gerald J.