ZR-1 Net Registry Forums - View Single Post - Noticed something interesting on my LT5...

bdw18_123 · 02-27-2010

Actually, Eric, the last picture you posted showing the cast-in date of my LT5 is on the passenger side. The re-stamped VIN is on the driver's side.

Here is another interesting piece of this puzzle. The piece that is between the block and the oilpan has a cast-in date of 3/8/90. This would seem to indicate that this LT5 was started one day and finished the next day. I don't know if that was something that would happen a lot or not.

Since the last 4 digits of the re-stamped MM number indicates that this LT5 was the very 1st build of the day the stamp was done, I would think that day would have to be the 8th of March, 1990. Here is a picture of my LT5 with arrows pointing to both cast-in dates:

The other strange piece of this puzzle is the fact that you can just make out what the number was that MM tried to grind out. It looks like it might be X0052299 (I added the underline here). I can tell for certain that the 1st two digits of the last 4 ground out numbers are both "2's". The last two could be "0's" I suppose, but the lower part of those numbers are more flattened out like the "9" stamp would be, so that is probably unlikely. If you look at the first picture in my first post, you can kind of see the ground out number.

If in fact it is true that the last 4 numbers originally said "2299", that would mean that this engine probably was always originally intended for #2299. Maybe MM had a new employee that accidentally stamped the last 4 of the VIN instead of the number that was supposed to be there. That would also mean that MM knew what engine was going in what car (the first year anyway).

The fact that there was a backlog in the middle of '90 makes that more likely since there would be more orders for ZR-1's than the number of built LT5's. In '93, this would have been the opposite. They were making way more engines than the amount of orders for ZR-1's that GM was sending, since they were making the rest of the engines ahead of time for the Z's all the way to '95.

02-27-2010	#39
bdw18_123 Join Date: Apr 2009 Location: Prather, CA Posts: 804	Re: Noticed something interesting on my LT5... Actually, Eric, the last picture you posted showing the cast-in date of my LT5 is on the passenger side. The re-stamped VIN is on the driver's side. Here is another interesting piece of this puzzle. The piece that is between the block and the oilpan has a cast-in date of 3/8/90. This would seem to indicate that this LT5 was started one day and finished the next day. I don't know if that was something that would happen a lot or not. Since the last 4 digits of the re-stamped MM number indicates that this LT5 was the very 1st build of the day the stamp was done, I would think that day would have to be the 8th of March, 1990. Here is a picture of my LT5 with arrows pointing to both cast-in dates: The other strange piece of this puzzle is the fact that you can just make out what the number was that MM tried to grind out. It looks like it might be X0052299 (I added the underline here). I can tell for certain that the 1st two digits of the last 4 ground out numbers are both "2's". The last two could be "0's" I suppose, but the lower part of those numbers are more flattened out like the "9" stamp would be, so that is probably unlikely. If you look at the first picture in my first post, you can kind of see the ground out number. If in fact it is true that the last 4 numbers originally said "2299", that would mean that this engine probably was always originally intended for #2299. Maybe MM had a new employee that accidentally stamped the last 4 of the VIN instead of the number that was supposed to be there. That would also mean that MM knew what engine was going in what car (the first year anyway). The fact that there was a backlog in the middle of '90 makes that more likely since there would be more orders for ZR-1's than the number of built LT5's. In '93, this would have been the opposite. They were making way more engines than the amount of orders for ZR-1's that GM was sending, since they were making the rest of the engines ahead of time for the Z's all the way to '95. Last edited by bdw18_123; 05-24-2011 at 05:28 PM.