Z28 Pulley question

[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?