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Hi guys ... I try to figure out what block engine I have unfortunately no luck the car.( 2003 convertible ). l look at the passenger side there is laser print number 2177nk 029365. . And in top there is 241 ......and when l look at driver side there is laser print number 2177nk. 026365. .... Than under the engine I find only this number 21570114 .... .. ldon't see bullseye in the passenger side ldon't know what's this ? The driver side if you zoom in
I have read that later LS1s have the same block and intake manifold as LS6s, but with LS1 heads and cam — which 241 heads are. It sounds and reads like you have exactly what you should.
I have read that later LS1s have the same block and intake manifold as LS6s, but with LS1 heads and cam — which 241 heads are. It sounds and reads like you have exactly what you should.
one more in agreement. GM had a shortage of LS1 blocks in early 2001 so they they started using their surplus of LS6 blocks for coupes and verts. All other parts remaining the same to the LS1 build (heads, cam etc) with the exception of the LS6 intake which became standard '01 forward. Some of the LS1 based F body cars also received the LS6 block at this time '01-'02. Then throughout the last few production years of the C5 they phased out the LS1 block and just used the LS6 block until C5 ended production.
If memory serves this is covered in the book " How to Build High-Performance Chevy LS1/LS6 V-8s" by Will Handzel.
No "bullseye" under the coolant crossover tube it's not an LS1 block. You can (not so easily) check the number on the back of the block just above the transmission flange for number 12561168 which denotes the LS6 block.
Last edited by Johnny Hardcore; Nov 16, 2023 at 09:30 AM.
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Originally Posted by redzg
I have read that later LS1s have the same block and intake manifold as LS6s, but with LS1 heads and cam — which 241 heads are. It sounds and reads like you have exactly what you should.
one more in agreement. GM had a shortage of LS1 blocks in early 2001 so they they started using their surplus of LS6 blocks for coupes and verts. All other parts remaining the same to the LS1 build (heads, cam etc) with the exception of the LS6 intake which became standard '01 forward. Some of the LS1 based F body cars also received the LS6 block at this time '01-'02. Then throughout the last few production years of the C5 they phased out the LS1 block and just used the LS6 block until C5 ended production.
If memory serves this is covered in the book " How to Build High-Performance Chevy LS1/LS6 V-8s" by Will Handzel.
No "bullseye" under the coolant crossover tube it's not an LS1 block. You can (not so easily) check the number on the back of the block just above the transmission flange for number 12561168 which denotes the LS6 block.
I have the Will Handzel book, too. It is rather dated info, but it is still a good read. A lot of info. On my book, the cover photo, and many inside, too, were taken at the now defunct Wheel to Wheel Powertrain, which was in Warren/Madison Heights, Michigan. Remember Kurt Urbans Nova, in Hot Rod Magazine? Well..... The (red?) truck on the cover is Kurt Urbans. Don't mess with that truck, trust me!!!
It's LS1 or LS6 ????
one more in agreement. GM had a shortage of LS1 blocks in early 2001 so they they started using their surplus of LS6 blocks for coupes and verts. All other parts remaining the same to the LS1 build (heads, cam etc) with the exception of the LS6 intake which became standard '01 forward. Some of the LS1 based F body cars also received the LS6 block at this time '01-'02. Then throughout the last few production years of the C5 they phased out the LS1 block and just used the LS6 block until C5 ended production.
