I hope somebody can help shed some light on this for me.Let me start by saying I have a 89 firebird with a lt1 and a 4th gen radiator.From what I have seen in other threads The top fitting on the pass. side goes to the overflow,The next one down goes to the throttle body on the drivers side.The third one down I don't know where that goes,the bottom one goes to the water pump themostat housing.On the drivers side the top one goes to the to the large port on the water pump,and the bottom one goes to the small part on the drivers side of the water pump.So my question is where does the third one down on pass side go,and how do the heater hoses hook up to the tb and the remaining two ports on the pass side of the water pump.It looks to me like the larger heater hose goes to the top port on pass side of water pump,and the smaller one goes to the bottom on the pass side,and the steam pipe goes to the bottom pass side of the tb.Is this right and where does the middle port on the pass side of the tb go?I would really apprieciate any help.Thanks.

I forgot to mention I have a t56 and those ports are plugged.

Anybody?

The 2 remaining ports on the water pumop are the 5/8" and 3/4" inlet and outlet for the heater core, but I am unsure about the third one down on the passenger side.

I would bypass the throttle body (unless you drive the car in the winter) and tke that steam tube hose that come staight off of the back of the heads to the 2nd port down on the pass side rad.

I just went with a normal radiator, bypassed the throttle body and ran the steam tube hose directly into a t fitting on the return radiator hose.

Also check out shbox.com, there is a lot of 4th gen info I used when doing my swap.

Thank you for your help.