ZL-1 stamping numbers

[GMH454]

COPO, I will dig them out on the weekend. I keep writing them down, but I always forget where I put them. I don't think I had a date code on the engine pad. Porterfield showed me Chevy copy paperwork (now where did I put that) that showed my engine number was in the middle of a sequence of racing engines supplied in around 1971 ( I think ). Pretty sure date was not part of the numbers. Maybe that's what the 61A was.
Also were numbers like my 107 common to all ZL-1s. Whats your got?

[COPO]

Just went down in the basement, front pad is stamped TO307ML, down near the oil filter is stamped 19N620923, which is the VIN for car #51. (block came frome original owner of car #51) Caps are stamped 356, Raised casting date looks like 1 1969 then 472 under it. I have read that the 472 is an inventory number and it is directly below the casting date. These numbers are cast upside down on the passenger side of the block near the front of the engine. I'll look a bit more this weekend when I have more time to see if these ar additional markings.

[COPO]

I would be interested in the numbers from your ZL-1 block. Specifically, the block casting number from the rear, the block casting date and inventory number from the driver's side of the block and the assembly date coded from the front pad. I have a '69 ZL-1 block as well and would like to compare numbers to mine.

[Edited by COPO (09-27-2000 at 12:21 PM).]

[JoeC]

Do both of the ZL1 blocks have the Winters foundry snowflake casting mark in front above where the water pump would be? Also do they have the screw in freeze plugs or the std. type sheet metal freeze plugs. Just curious. Chevy was also selling a Can Am block with the 4.400 in. bore and siamese cyl. that was used for racing. I think this is the one that Yenko and Bill Smith sold in the 80's.

[COPO]

Winter's snowflake and screw in freeze plugs on mine. I've looked at the casting very carefully and it appears to be virgin stampings and the fact it was purchased from the original owner of car #51 leads me to conclude 99.99% it is legit.

[GMH454]

COPO, when Porterfield gave me the racing sheets he told me to look at the engine very carefully. When I looked in the lifter valley I was very surprised to find a set of stampimgs. Get out the flashligt and find someone with REALLY good eyesight. Mine were stamped on what look like bosses in the valley. In between watching the Olympics here I WILL dig out the remainder of the numbrers. Also check to see if your block is stamped with the 356 anywhere else other than the caps.

[Kurt S]

Thanks all. I don't watch the Bench Racing section so I missed those postings. I know John but didn't realize he worked on the ZL1's.
It will be interesting asking him some of the assembly questions we have.

Kurt

[GMH454]

COPO, the 107 is on the outside of the block at the back on a kinda boss at the top of the bellhousing area.
Cast numbers are date 1.28.69, numbers below are 128 number in circle to the right is 6.
Checked Porterfields letter (for which I am very grateful of)and the stamped number on the pad - 1-8880-61-A may be an order number.
McLaren had orders starting with 1-8880- also. Though thinking about it they should have been Can Am (Reynolds Blocks Hmmmm)
Does anyone know what the 107 means and do other ZL-1 engines have numbers on the blocks matching their cap numbers. ANY info appreciated

[JoeC]

GMH454, Do you know the cyl. bore diameter of your block? The CAN AM block started at 4.400 in. dia. and had siamese cast iron liners. I believe the Can Am Reynolds Alu. Blocks had no liners.

[GMH454]

Good point Joe. Its 40th over a standard bore. Which is funny cause I think the Green Book says they should only be bored 30th. Still looks to have plenty of strength between the bores, and they are sleeved. I have checked them before and they are the standard Zl-1 numbers.
Are the ZL-1 casting dates known anyone ?