I just put my L98 in the car that used to be an L03. I need to know how to route all the coolant lines now. If someone has a diagram they can post including the TB, intake manifold and heater control valve that would be awesome. Even a brief description would be a huge help. Thx.

L03 is TBI, right? I have a 305 TPI in my 89 Firebird, and an 88 Camaro TBI (wrecked) out behind the garage, so I can take a close look at them for you. If I can't describe it accurately, I can take a digital picture tomorrow night.

pretty much everything should be the same. The only difference is the coolant output from the manifold. on the TPI it will come out the front of the manifold IIRC.

The way is is *supposed* to be is the coolant comes out the manifold, goes through the throttle body, and then goes to the plastic vacuum operated heater valve. From the heater valve, depending on whether vacuum is applied to it, the coolant runs to the heater, and then to the right bank of the radiator, or if the heater is off, it just runs right to the right bank of the rad.

I recommend skipping the throttle body, unless you live in canada, or alaska or something.

Also, an important thing to keep in mind. TPI engines run with a reverse rotation water pump. Make sure you don't put a standard rotation water pump in its place, it will cool like **** (don't ask...it was embarassing).

You will know if the pump is reverse rotation by looking at the pulley. If it is serpentine, and driven of the rib side of the belt, it is standard rotation. If it's driven off the flat side, it is reverse rotation.

Also, depending on year and engine, your heater return may go back into the water pump, instead of into the radiator.

If I'm vague in any way, or missed something else you wanted, let me know, and I'll go outside and peek at the cars

edit: I got a pic scanned from the service manual...soon as I find webspace to upload it, i'll post.

My apologies to anyone running less that 1024x768.

Here's a big ol honkin diagram for ya:



and here's one I stumbled over while surfin the boards:

Thanx alot.