2nd Ed 73-74 Tech Manual, Page 86, No NCRS reference for a 73 LS4 AIR Diverter Valve

[George H.]

My 73 LS4, M21 with factory AC, which I've owned for 37 years, has the original AIR injector pump 7801149 date coded 13032S (5/10/73 2nd shift, model S). I assume that S is for Corvette model. ? The pully is stamped 330552DH and the diverter valve is stamped 7034481. Why is there no reference made in the Air Valve Chart for a 1973 LS4 valve on page 86?

[Harmon C.]

Re: 2nd Ed 73-74 Tech Manual, Page 86, No NCRS reference for a 73 LS4 AIR Divirter Va

When that manual was made 1999 The team did not have the information.

[George H.]

Re: 2nd Ed 73-74 Tech Manual, Page 86, No NCRS reference for a 73 LS4 AIR Divirter Va

Thanks for the update. That make good sense. My 73 has never been judged or has it been painted. Recently became a member of NCRS and purchased the 73-74 judging guide. Going through all the pages addressing operations, interior, mechanical, etc. Quite the book. I've tryed my best (second owner purchased it in 1980) to keep everthing GM original. A Florida car with 71,270 miles on it. The guide is extremely helpful in knowing if all the parts are still original, original GM replacements, or what I need to get fixed before I think about haaving it judged. Needs a new front bumper cover and I plan to keep that original. Big $$$.

[Joe L.]

Re: 2nd Ed 73-74 Tech Manual, Page 86, No NCRS reference for a 73 LS4 AIR Divirter Va

My 73 LS4, M21 with factory AC, which I've owned for 37 years, has the original AIR injector pump 7801149 date coded 13032S (5/10/73 2nd shift, model S). I assume that S is for Corvette model. ? The pully is stamped 330552DH and the diverter valve is stamped 7034481. Why is there no reference made in the Air Valve Chart for a 1973 LS4 valve on page 86?

George------


The "S" does designate the model of the pump. However, that model is not exclusive to Corvettes. It was used for MANY GM cars and trucks of the period for quite a few years from 1968 to 1974 and later.

[George H.]

Re: 2nd Ed 73-74 Tech Manual, Page 86, No NCRS reference for a 73 LS4 AIR Divirter Va

Thank you Joe, I appricate the update.