ur7x

iTrader: (2)

My project is to swap in a lightly warmed over 1991 9C1 350 with new "062" Vortec heads into a 1983 LG4 Z28... Everything is going well so far... And then I hit the water pump.

Turns out that my donor 1991 Caprice water pump lacks the "return" nipple for the heater core... I have in my collection a few reverse rotation water pumps and all but one lack the heater core return nipple or plugged port (and that one is a rusted mess).

So If I want to order a new water pump for the car is there a part number (or exchange number ) or a year make model. (parts counter guy) That is reverse rotation AND has the heater return provision. When did GM delete the heater core return? (year) and for which models?

Next question. The TBI intake had two stainless "plugs" in the back crossover coolant ports of the intake manifold. When I install the GMPP TBI/Vortec intake do I leave them open or do I block them some how?

Thanks

sofakingdom

iTrader: (1)

Radiators often have the cold-side (heater core return) port you need.

Drew

iTrader: (58)

Pretty sure you would have a harder time finding a replacement WP without the port, since it sure seems like most, if not all come with the port and a plug for cars that don't need it. Kind of annoying if you want to stay correct and your car didnt have the port originally.

ur7x

iTrader: (2)

Thanks.

The 83 LG4 did have the heater return port/nipple on the pump, but of course that water pump also turns the wrong way. The 1983 Rad lacks the heater return port and is still in good shape and would rather not replace the rad before it is done.

Does anyone know of a factory system that had a reverse rotation pump AND use the pump as the return point for the heater?

Any advice on blocking off the rear intake coolant crossover on a Vortec intake?

Drew

iTrader: (58)

Look up a WP for any 88-92 Camaro with a V8. Most, if not all have the port.