De-Coding LT5 Block Numbers - ZR-1 Net Registry Forums

LGAFF · 06-13-2010

Not sure if these are posted or not...

ZR-1 Block #s

10090511...350.....90....2...LT-5, ZR1 Vette, 375hp

10153558...350...91-92...4...LT-5, ZR1 Vette, 375hp

10199001...350...93-95...4...LT-5, ZR1 Vette, 405hp

LGAFF · 06-13-2010

I thought this might help in decoding Dominic's block, but I did not find this referenced on the spare block that I have.

It has 10ZSH 91100015 on the side.

I did notice on the front drivers side it is numbered with 1059...I am wondering if this is the sequence of LT-5s built...the car is # 702 so its possible.

XfireZ51 · 06-13-2010

Lee,

Maybe Gordon Killebrew could be of help on this.
Didn't my block have the 9001 number?

LGAFF · 06-13-2010

Found it, the 90 actually has a 91 block stamp 10153558

Also Block and Girdle are mated with the same stamped # 1059

1989ZR1#74 · 06-14-2010

10ZSH 91100015 ??

10ZSH: 1990 MY 375HP/350CI, Manual Transmission Electronic A/C

91100015 is short 2 digits. Are you sure that's the number?

It should start with an X for MM Stilwater
last 4 are that days sequence, but the date derivative can't be right.
So should look something like this:

X911100015:
X = MM
9 = 1989
11 = November
10 = 10th
0015 = 15th LT5 assembled that day.

Eric

LGAFF · 06-14-2010

I will look, does your motor have matching stamps on the block and girdle?

Date Stamp from #702

1989ZR1#74 · 06-14-2010

This LT5 came from the 702nd 1990 built. It's VIN is: 1G1YZ23J8L5800702
It is/was a Black/Black

It's block casting date was Tuesday 10/03/1989. Unlike non LT5s that have raised cast in dates the LT5 casting date is "stamped" into the block. This number will supesede the date on the "oil pan" boss.

LGAFF · 06-14-2010

So

10ZAA X 206170003

Is this an LT-5 produced on 6/17/1992 and the third motor produced?

This is Dominics motor.....VIN stamp area does not match the car

This is the stamp were the VIN traditionally is

100991 14

Eric870 · 06-14-2010

My 1990 #740, the motor was built on 11/20/89 5th motor of the day.10ZSHX911200005

Question: My Build Sheet Date of my car is 89/321. Does that = 11/16/89? That is 4 day before my motor was built.

bdw18_123 · 06-14-2010

More LT5 stamp weirdness? My '90 ZR-1 LT5 re-stampings are still a mystery also.

Here is a recap of mine:

#2299, MM LT5 number re-stamp:

VIN cross-out & block casting date (passenger side of engine):

VIN stamp (driver side of engine):

Invoice for the car has 5/22/90 as the "PRICED" date, which I think is supposed to be the build date? And 11/22/90 is when the car was delivered to the original buyer.

06-13-2010	#1
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	De-Coding LT5 Block Numbers Not sure if these are posted or not... ZR-1 Block #s 10090511...350.....90....2...LT-5, ZR1 Vette, 375hp 10153558...350...91-92...4...LT-5, ZR1 Vette, 375hp 10199001...350...93-95...4...LT-5, ZR1 Vette, 405hp __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359 Last edited by ZBrink; 01-25-2025 at 04:49 AM.

06-13-2010	#3
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,686	Re: ZR-1 Block Numbers Lee, Maybe Gordon Killebrew could be of help on this. Didn't my block have the 9001 number?

06-13-2010	#4
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: ZR-1 Block Numbers Found it, the 90 actually has a 91 block stamp 10153558 Also Block and Girdle are mated with the same stamped # 1059 __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359 Last edited by LGAFF; 06-13-2010 at 10:34 PM.

06-14-2010	#5
1989ZR1#74 Join Date: Jan 2009 Location: Scottsdale, AZ Posts: 700	Re: ZR-1 Block Numbers 10ZSH 91100015 ?? 10ZSH: 1990 MY 375HP/350CI, Manual Transmission Electronic A/C 91100015 is short 2 digits. Are you sure that's the number? It should start with an X for MM Stilwater last 4 are that days sequence, but the date derivative can't be right. So should look something like this: X911100015: X = MM 9 = 1989 11 = November 10 = 10th 0015 = 15th LT5 assembled that day. Eric Last edited by 1989ZR1#74; 06-14-2010 at 12:35 PM.

06-14-2010	#6
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: ZR-1 Block Numbers I will look, does your motor have matching stamps on the block and girdle? Date Stamp from #702 __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359 Last edited by LGAFF; 06-14-2010 at 02:06 PM.

06-13-2010	#2
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: ZR-1 Block Numbers I thought this might help in decoding Dominic's block, but I did not find this referenced on the spare block that I have. It has 10ZSH 91100015 on the side. I did notice on the front drivers side it is numbered with 1059...I am wondering if this is the sequence of LT-5s built...the car is # 702 so its possible. __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

06-14-2010	#7
1989ZR1#74 Join Date: Jan 2009 Location: Scottsdale, AZ Posts: 700	Re: ZR-1 Block Numbers This LT5 came from the 702nd 1990 built. It's VIN is: 1G1YZ23J8L5800702 It is/was a Black/Black It's block casting date was Tuesday 10/03/1989. Unlike non LT5s that have raised cast in dates the LT5 casting date is "stamped" into the block. This number will supesede the date on the "oil pan" boss. Last edited by 1989ZR1#74; 06-14-2010 at 05:48 PM.

06-14-2010	#8
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: ZR-1 Block Numbers So 10ZAA X 206170003 Is this an LT-5 produced on 6/17/1992 and the third motor produced? This is Dominics motor.....VIN stamp area does not match the car This is the stamp were the VIN traditionally is 100991 14 __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359 Last edited by LGAFF; 06-14-2010 at 08:53 PM.

06-14-2010	#9
Eric870 Join Date: Apr 2009 Location: Portland OR Posts: 165	Re: ZR-1 Block Numbers My 1990 #740, the motor was built on 11/20/89 5th motor of the day.10ZSHX911200005 Question: My Build Sheet Date of my car is 89/321. Does that = 11/16/89? That is 4 day before my motor was built.

06-14-2010	#10
bdw18_123 Join Date: Apr 2009 Location: Prather, CA Posts: 804	Re: ZR-1 Block Numbers More LT5 stamp weirdness? My '90 ZR-1 LT5 re-stampings are still a mystery also. Here is a recap of mine: #2299, MM LT5 number re-stamp: VIN cross-out & block casting date (passenger side of engine): VIN stamp (driver side of engine): Invoice for the car has 5/22/90 as the "PRICED" date, which I think is supposed to be the build date? And 11/22/90 is when the car was delivered to the original buyer. Last edited by bdw18_123; 06-14-2010 at 09:12 PM.