Expert help needed- matching intake manifold 1968 C20 327

[GerhardH]

Hi Guys
this research makes me nearly crazy, maybe you with your experience can enlight me a little bit:

My truck:
1968 C20 Camper 327 with automatic choke, automatic transmission TH400, power brake (SPID: L30,N40,M49)

For me is very interesting what was the
Original block casting number maybe casting number 3791362, 3858174, 3858180, 3892657, 3903352, 3914660, 3914678, 3933180 or 3956618 with GM# 3937295?
Original intake manifold casting number probably # 3919803 (GM#3931575)
Original carburator number and manufacturer with wich choke assembly probably Rochester Quadrajet 4MV 7028213 with divorced automatic choke

Maybe somebody has some pictures, information, documents etc...
Highly appreciated!

According protect-o-plate the original engine ID was: VO426YV (means 327 from Flint for 3speed automatic transmission with 4BBL Carb, and the original Carburator was C (means Carter) and as the date vehicle originally placed in service (protect-o-plate was 6-29-68) and the car assembly was on 05-02-68 (build sheet) and the engine asssembly was 04-26, assuming 04-26-68.

The build sheet stated Carburator - 8213, assuming means 7028213 Rochester Quadrajet 4MV Carburator manfactured by Carter (MFD By Carter Carburetor for GMC 7028213).

The engine was probably changed during guarantee period with a 327 block 3959512 with ID CE7P27140 as CFB = Counter Fitted Block.

The engine has actual an Edelbrock Carburetor #1406 with Carburetor spacer and intake cast # 3960364 ( I cannot find this cast # in interchange books, the only information I found was in internet as follows:

The 3960364 manifold was used in 1968 and was cast either 3919803 or 3960364.
&
This manifold has been found with the casting number 3960364 on it where someone forgot to change the casting number of the mold in the cope. They apparently cast a bunch of them before the QC guys caught on and changed it (too many to scrap).

The interchange manual stated for 1968 327 truck intake manifold casting number 3872783 four barrel cast iron, some other sides say until 1967 only and the 3872783 manifold has sqare bore design (Holley, Carter?), assuming the Quadrajet need spread bore design? The Chevrolet truck part catalog october 1969 stated for 66-67 GM# 3888885 (casting number 3882858) und for 68 GM# 3931575 (casting number 3919803).