I have a lunchbox in the rear of my FJ40. Hate it ... oops, sorry, HATE it. That truck is outright scary on wet and icy roads. You really need to be careful with the throttle going around turns on pavement.
I have a Truetrac in the front of my 4R, with an ARB in the rear. I like the...
Common part. Just about anyplace including the autobox stores and NAPA. I bought mine at Fuel Injector Connector - https://www.delcity.net/store/Fuel-Injector-Connector/p_797788.h_797789.