Nick D.

Anyone know how to identify the various LS1 engines? I am primarily interested in the passenger car motors from the Camaro/Firebird and the Corvette. The May issue of GM High-Tech Perf has a good article on head spotting but I haven't seen anything on block id'ing. My 99 motor has the casting # 12562174 on the back of the block below where the driver head bolts on. This is probably the casting number of the block but I haven't seen anything in print that would verify year, application, etc. Anybody got any info?
Thanks,
Nick

rwj383

the last 3 numbers of the head par number can be found on the lower right or left corners of the heads, depending on casting number. 241's (ls1 heads 2001 and newer model year) are located on the bottom right corner outside the valvecover. 853's (2000 and older ls1) are located on either corner, i have found. So, if no head suffix number is readily visible at first, look back under the cowl at the lower corner of the head. 243 is 2001 and newer LS6 heads.
hope this helps.


[Modified by rwj383, 11:58 AM 5/7/2003]

Nick D.

rwj,
Thanks, I was aware of the head designations from the article mentioned. For reference the "853" , "241" and "243" are the last three numbers of the casting number 12559853 (97-00), 12564241 (01-03) and 12564243 ( 01-03) LS6. These appear under the valve cover. The numbers mentioned do not include the 4.8, 5.3 and 6.0 truck applications although that would be good to know also.

What I'm looking for are the block casting numbers and location of the date codes for all the passenger cars (Camaro/Firebird/Corvette) that use the LS1.
Thanks,
Nick

rwj383

aahhh, i see. Well, i got my original 2001 LS1 motor on an engine stand out in garage. Let me go look.....

Nick D.

rwj,
That would be great! My friend has a 2001 Camaro motor with the block casting of 12559378 and the 241 head casting. It will be interesting to see if the Vette motor is the same. I don't know why it wouldn't be.
Thanks,
Nick