Doffing

Hello. I got a used 2001 z28 and there is some confusion about the engine. The person i got it from showed me text from a previous owner saying engine was swapped with an ls6 engine. I dont believe it is an ls6 but how can i tell for sure? I want to get a retune but im not sure what to put down, ls1 or ls6. Or would it even matter to the person tuning the computer?

N20zuki

It doesn't matter to the person tuning... 01+ came with a LS6 intake manifold so that may be where the confusion came from. But start by posting the cylinder head casting numbers as that is going to be the easy way to tell.

Doffing

I see a 241.

HCI2000SS

iTrader: (2)

241's were on the LS1

Mappinsj

It is an ls1 then

Doffing

Ok so it is an ls1 good to know. Thanks for clearing that up for me.

SouthernRex

He was probably confused because of the intake manifold from the LS6 as mentioned above (which came factory for 01-02 LS1 F-bodies.)

Chris25

iTrader: (1)

Some late model Fbodys had an LS6 block with 241 heads and an ls6 intake that maybe what the confusion was...

Chris25

iTrader: (1)

I remeber reading it was like 5-10% of 01s that came with an LS6 block. Check the block code to be sure.

Deeohgie69

iTrader: (3)

Yeah and don't use the bullseye method, there's no truth to it. According to that method, mine is an ls6 block. I used my phone and slid it behind the block and firewall on the drivers side and took a bunch of pics until I lucked out and got the number. A lot of people say to use a mirror, but that is too much frustration.

Either way, it's just the block, everything else is the same. Although some people swear that the ones they've had that had them ran better than the others. One guy even said that he's had 4 all together and if you gave him two cars, one that had that block and the other just an ls1 that he could tell you what one had the ls6 block. I find that hard to believe, but I've not driven one.