1996 surging while cruising....searched before

OK I have a 96 XJ 2 wheel drive auto,stock lift.I have searched and searched for issues related to surging when cruising/rough-ish idle.OK have tried both o2 sensors replaced,cat is clean through (Magnaflow) removed to inspect.Tried different TPS,ECM,Map sensor, removed trans controller fuse to test trans solenoids...still surges around 200-300 rpm's,even with trans controller out of the game.Problem is more noticeable when hot/running temp.No vac leaks either.Also changed the Fuel Pump,Bosch brand,Fuel pressure regulator in the tank...another found thread I can start...It IS replaceable.anyways I can not figure it out.The manifold/header is cracked but I am hard pressed to believe it will fix the surging.New one to be installed.When it acts up it feels exactly like a clogged cat,falls on it's face,but when it nuetral it revs up fine plus slight speed cruising 35 mph or so surging.It bugging the crap out of me. ...hopefuly some one has the direction to go next.Have not tried diff crank sensor though,I don't think it would change the problem either.