There is a 1964 Max Wedge block currently on eBay ....Does anyone know what the numbers on the oilpan lip/ face signify ??
The number is 3 26

http://www.ebay.com/itm/MOPAR-426-MAX-WE...347&vxp=mtr

Probably relates to the date it was first machined being that it falls between the casting and final assembly dates.

My MW block cast on 12 feb 1963 and is stamped with the number 3 20 built 16-5 (63) LC
This block is cast the day before 11 February 1963 with the number 3 26 built 7-11 (63) HC

They seem to be the wrong way around? I thought it may have been total MW blocks so far.

I also have a MW block cast on 12th October 1962 with the pan # 1 23 built 2-2 (63) HC

.all 426 blocks

While it never hurts to try and learn more on details like that I wouldn't put too much weight on that stamping. The casting date looks right for a 64 MW as does the top pad stamping, I have no doubt that one is a real one. I don't see an issue with the asking price either, very rare part as the seller describes. That said, I WOULD be concerned about the cracks he mentions in the main saddles, small or not, cracks tend to spread.

I tend to agree Scott it all looks genuine. I was just wondering what these numbers represented when I saw them but never asked.

You could be right on the machining date but seems a wide spread.
The 2 HC blocks where cast one day apart but built 9 months apart ! ...that is quite a period to sit around ,do you think?

Both mine are 426 pre stage 2 whereas this block (case day after mine) is a stage3 engine. i.e skips over the stage 2 altogether.thats pretty strange

I don't find the casting vs assembly date to be strange, actually that's quite normal, especially for low production HP engines like MW's and Hemis. Many blocks that were destined to become HP builds were allowed to "season" before being built, this took time and temperature variables, sometimes from being stored outside in the open environment for months or even years.

Mopar did some under the table politicing as far as the 1963 "Stage Two cars and motors" are concerned, according to Tom Hoover at one of the old Mopar drag seminars in the mid 1970s all the "Stage Two cars" had hand modified combustion chambers, same thing on the intake manifolds and the later stage three carbs and camshafts. He said they where not production line made, special assembled off the line, for drag racing only I've look at a lot of Max Wedge heads at a lot of swap meets and at races in SO CA ,AZ and Nevada and I have never saw or know any other Mopar racer(Landy, Bagshaw, Lambeck, Hickman, Deana, Hale, McCanless and so on, that has ever seen a set of the production heads with the Stage Two head casting numbers on them IHTHs