Thank you! That helps a lot!Welcome to TBN
JD 820 with 3 cyl engine has open center hyd's which requires a special hyd block to correctly attach a FEL control valve. Believe it or not I sold JD 820 utility tractors when they were new! Below isa photo showing how to attach the control valve hoses to an 820. Part # for block(key 28) is W21205
Thank you!According to Tractor Data you have an open center hydraulic system. The only thing on it may be your three point hitch but you DO have hydraulics on board. You'll need to cut into the pressure line at some point, run the pressure to your loader control, then return to continue the supply to your three point. You may need a hydraulic shop or tractor dealer to make the connections but it can be done and is not terribly complicated. TractorData.com John Deere 820 tractor information