�73-74 TM 3rd Edition, Page 185 �Emission Control System� Part #7034481

[George H.]

elbow and outlet tee

[Joe L.]

The diverter valve connects to the air injection pump via an elbow. My pump on my ’73 LS4 is embossed 7801149 and is date coded 13032S. The diverter valve is embossed 7029190. My question is this. As part of the air pump assembly, there is a mounting hardware part embossed 7034481 that attaches to the diverter valve and air pump. Is that part number what we list as, “Diverter valve, elbow and outlet tee – zinc die-cast? It appears we don’t reference that GM part number. I assume part #7034481 is the elbow.

George Hunt

George------


7034481 is the CASTING/PART number for the diverter valve outlet tee. It is a component part of the diverter valve assembly and was never available separately. It was actually used on many different diverter valves. Because it's so prominent and the only easily seen part number on a diverter valve assembly, some folks seem to think it's the part number for the diverter valve, itself. It is NOT.

The diverter valve and the outlet tee are, indeed, cast of zinc diecast material.

The elbow for your application was GM #3951346 and is a separate part. It was cast of aluminum.

By the way, the 7801149 number you found on your AIR pump is NOT the part number for the pump assembly. It is the casting number for the pump's backing plate. It was used on many different AIR pumps over the 1968-75 period. Your original pump part number was GM #7803943. Unfortunately, this number appears nowhere on the pump.

[Leonard M.]

embossed 7029190". Here is a picture of the correct elbow. What pulley do you have on your pump? If you don't have it, the correct 73-74 BB one is difficult to find.
DSCN9211.jpgDSCN9213.jpgDSCN9214.jpgDSCN9212.jpg

[George H.]