Z28 Pulley question

[ctbZ]

Is it possible that an early February 1970 z28 would be equipped with a 3932456dv water pump pulley or did they all get the 3976060ap?

[USER-3965175]

Not possible, the 3932456 DV pulley for 1969 Z28 is 7-1/8" diameter - 1970 Z28 used the smaller diameter 5-7/8" 3947824 BV pulley which was also used on 1969 L78 engines

The 3976060 AP deep groove water pump pulley was used on 1970 L78 Camaros and on 1971 Z28 Camaros

USER3965175

[YENKO DEUCE REGISTRY]

I believe the 6060AP was also used on the '70.5 Z's, and the 824BV is the replacement version.

[al8apex]

not sure what a 70.5 Z is, they only made 1970 Camaros and 1971 Camaros

http://www.yenko.net/ubbthreads/images/graemlins/smile.gif

[YENKO DEUCE REGISTRY]

70.5 = 'Seventy and a half'

[USER-3965175]

[ QUOTE ]
I believe the 6060AP was also used on the '70.5 Z's, and the 824BV is the replacement version.

[/ QUOTE ]

Car Magazines originally coined the 1/2 year term with the 64 1/2 Mustang and again with 70 1/2 Camaro not GM

Cowl tags, door vin labels, Build sheets, assembly manuals and parts catalogs list 70 as year of production not to mention your pink slips

Pulley's listed in GM Parts Catalogs are scaled down from usage on the assembly line production and do not reflect actual usage on the assembly line

A Van Nuys Build Sheet for a 1970 Z28 dated June 17 1970 lists the "BV" code for the water pump pulley which is the 3947824 "BV" pulley

This build sheet is late engough to show that the "060" listed in the assembly manual under RPO Z28 that was to replace the "824 BV" pulley did not occur until almost the end of 1970 production

Early 1971 Z28 Camaros used the "060 AP" for a few months and then switched the "647 AP".

The "060" is only listed thru September 1970 in parts catalogs for 1970 model year only and then for the 1971 model year parts catalog dated September 1970 the "647" replaced the "060" as a service only pulley

Opinions and beliefs do not provide accurate information, only build sheets, assembly manuals and correct original cars can provide the actual usage for parts

USER3965175

[Jonesy]

What does the 74 z/28 use?

[hiperf69]

Hi guy's,I have pulled both a '72 and'73 original Z-28 apart and both (to my surprice) had 3942456 "DV" pulley's which according to the '73 Ass'y. manual is correct.Why would GM go from "DV" in '69 to a 060 "AP" in '70 and then go back to a "DV" in '72-3?
To what I remember all the Sm. Dia. pulley's,824's,060's and 847's(replacement') were BB only.Along with '69 only 640's.
Would a Yenko Nova use a "AP" or a "DV"?
Just trying to understand what I have seen.Joe.

[Mr70]

I think those 1974 245Hp 350 Z/28's woulda used the #3995647AP.

An interesting side note to this is that Joe P. is still the original owner of a 1970 L-78 Chevelle today.While breaking it gently down to do a complete resto on it,he found it was assembled with a deepgroove #3947824BV fan pulley,yet the parts books AND his buildsheet state it should have a deepgroove 060AP pulley.
His is an early build of August 1969.
While being judged DIAMOND at the NCOA 16 years ago,the judges gigged him for the pulley,as he left the original BV on it.
He said he didn't like the judges decision,but understood it as they were going by the books,and he by what his car was actually holding.

[YENKO DEUCE REGISTRY]

Deuces have 6060AP's, they were all built in 05D, 06A & 06B.

[Nova Research Project]

Assembly manuals and parts histories are littered with cases of part numbers moving in and out of production. Part A replaced by part B only to be replaced again by part A. Might be related to parts suppliers switching. Or to use up stock of parts in the warehouse. Engineering changes that did not really solve the problem. Short of going to dig up the Engineering Change document, you will have to rely on direct observation. I.e. Normal Observable Practice for the cars themselves to determine the Normative Practice as CRG says. In the end it might be like the 065 - 811 waterpunp usage. That being for many months either could have been used on the assembly line.

FWIW 3947824 was replaced by 3976060 3-70 in the 65-70 PH. And the 10-70 Parts book lists 3976060 as for all 69-70 Special High Performance 350,396,427,454s as well as Camaro 302 and Special High Performance 350. The Nova AIM lists 3976060 with no replacements between 4-69 and at least 1-70.

Greg

[YENKO DEUCE REGISTRY]

Thanks Greg! The NOP on Deuce LT1's was the 6060AP.

[L78steve]

What would a 70 L/78 Nova 02C have? 6060?

[L78steve]

[ QUOTE ]
What does the 74 z/28 use?

[/ QUOTE ]

I had a late 74Z and I don't recall it having deep groove pulleys.