'65 L79 with p/s correct pulleys?

[Tony S.]

Can someone help me identify the correct pulleys for my application? I've got a '65 327/350 hp car with p/s but no A/C. Which are the correct water pump and harmonic balancer pulleys? Photos would be really helpful.

I've done research in the archives and can't find an exact match to me car.

Thanks and happy Thanksgiving to all.
Tony

[Jack H.]

Re: '65 L79 with p/s correct pulleys?

Crack open your copy of the AIM book. Turn to UPC 6, Sheet 3 and the basic pulleys are called out by GM PN. Then, turn to the N40 section in the options at the rear of the book and you'll see the extra pulley that's defined for pwr steering.

No need to see pictures. Original pulleys were embossed with their GM numbers...

[Tony S.]

Re: '65 L79 with p/s correct pulleys?

Jack. I looked at my AIM before posting. Regretably, the AIM is not overburdened with great clarity.
Tony

[Bill C.]

Re: '65 L79 with p/s correct pulleys?

Anthony,
65 L-79 does not use an add on pulley as the lower HP engines do, it uses two groove deep groove upper and lower pulley's and the offset cast iron single groove P/S pump pulley, and of course the correct unique alternator pulley. Be certain you have the correct lower pump mount bracket also that is a stamped affair with two tube style supports that the longer bolts pass thru, correct original earlier 6-5 lower brackets are of a stamped only design, very similar to the later to come BB lower bracket will not clear the larger balancer.

This year was first application for P/S on an engine that utilized the hi perf 8" balancer so the lower bracket required redesign. I'm sure the balance of inventory of the earlier design was used up on the lower hp engines until gone and later the redesigned bracket is found on all versions.
I have attached pics of the pulleys/belt arrangement.

Correct pulleys can still be found on auction sites, driveline, etc. Or excellent functional correct part# pulleys are available new from many sources.

Nice option to have! Also be sure your p/s valve has the correct internal spring for 65 or it the system will feel much to sensitive or in other words, "have to much power assist"

[Herb F.]

Re: '65 L79 with p/s correct pulleys?

Bill. You are putting me on the right track. It appears that your crank pulley is a double--not a triple. Correct?

Can you tell me the diameter of the lower crank pulley?

Tony

[Bill C.]

Re: '65 L79 with p/s correct pulleys?

Correct, its a dual groove, fairly common pulley. I cannot get back to it to measure soon but any catalog should have the gm # id'ed. Try Paragon or CCentral, use the 350-365-375 application.
Thee was no 3 groove pulley, the third is actually an additional single pulley added on to the base 2 groove pulley , that set up uses the stamped non-offset P/S pulley. FYI, the add on single pulley cannot be used with the 2 groove deep pulley, it will not match up.

[Wayne M.]

Re: '65 L79 with p/s correct pulleys?

Correct, its a dual groove, fairly common pulley. I cannot get back to it to measure soon but any catalog should have the gm # id'ed. Try Paragon or CCentral, use the 350-365-375 application.
There was no 3 groove pulley, the third is actually an additional single pulley added on to the base 2 groove pulley , that set up uses the stamped non-offset P/S pulley. FYI, the add on single pulley cannot be used with the 2 groove deep pulley, it will not match up.

Bill -- nice pics; I figured if Tony was asking the question then the AIM was not providing the answer; tried myself and gave up .

I believe what you are saying is that the water pump and crank pulleys are the same 2-groove units that would be used on an L79 w/o N40 or C60 (or the L76 w/o C60, or L84). In that case the upper is 3770245 (P&A30 lists as 7_1/8" OD) and the lower is 3858533 (P&A30 lists as 6_3/4" OD). But in the case of P.S., the #2 groove of the water pump pulley is not used, and the #2 groove of the crank pulley drives the power steering pump.

IMO, the addition of the L79 engine to the lineup in 1965 was not well thought out in terms of information in the AIM, nor in the P&A30 catalogs (using revisions of March and July '65).

[Bill C.]

Re: '65 L79 with p/s correct pulleys?

Bill -- nice pics; I figured if Tony was asking the question then the AIM was not providing the answer; tried myself and gave up .

I believe what you are saying is that the water pump and crank pulleys are the same 2-groove units that would be used on an L79 w/o N40 or C60 (or the L76 w/o C60, or L84). In that case the upper is 3770245 (P&A30 lists as 7_1/8" OD) and the lower is 3858533 (P&A30 lists as 6_3/4" OD). But in the case of P.S., the #2 groove of the water pump pulley is not used, and the #2 groove of the crank pulley drives the power steering pump.

IMO, the addition of the L79 engine to the lineup in 1965 was not well thought out in terms of information in the AIM, nor in the P&A30 catalogs (using revisions of March and July '65).

Wayne,
All agreed. Very confusing, been there. It appears to be one of those items that was pushed thru the design/engineering system, probably by marketing and was not documented properly. Another early year rush thru I assume

1965 sure was a year of change!

[Tony S.]

Re: '65 L79 with p/s correct pulleys?

Wayne/Bill. Thanks for your input! It's much appreciated. The AIM is little or no help. The introduction of L79 with N40 did not translate well in the AIM.

From my research, it would appear that the following pulleys are correct for a 1965 L79 with N40 (but no C60):

Water pulley: 3770245 (deep groove double pulley).
Crank pulley: 3858533 (deep groove double pulley).
P/S pulley: 3824720.

The 1965 JG (5th edition) is incorrect as it calls for a three grooved crank pulley (1965 JG, page 117).

Are you out there Mike Murray?

Best,
Tony