i started a project last summer...it's going slowly, but going..so far what we've done - the car has 2004 GTO LS1, 4L60E, 4th gen rear, bilstein shocks, eibach pro springs, upgraded suspension bushings, tie rods etc, customised a/c housing (didnt clear one of the coils), customised brake lines, cracked windshield, old parts in the trunk and in need of new paint...and now the fuel lines have to be cut to match with ls1 fuel lines, i'm going after factory look under the hood)))...and i get to use 4th gen fuel tank with evap on it...smog legal nice daily driver it would be..

Cool. Lets see some pics man!

its not representable, but ill find some good ones

Can you get some pictures of the exhaust setup and how you got the smog stuff hooked up? The smog components are my biggest worry doing this swap and would like to see some ideas.

exhaust is far far in the future, still cutting lines for the fuel.they snapped the fuel pump harness at the junk yard, and now i have to find a new one, be....
i'll be running Edelbrock shorty headers, stock cats, stock conversion pipe and Edelbrock Cat back, if it's of any help..
are you going to leave evap up front, or are you using a 4th gen tank?

If I can get my hands on a 4th gen tank, might as well swap it in and clean up the engine bay some right? The reason I asked about the exhaust is because doesnt the LS1 use something like 4 O2 sensors? I was just wondering how you did that up? Also, the rest of the smog stuff fit right in with no issues?

I'm still working mine up, but I found a 4th gen tank complete on eBay for less than the cost of a new pump. The evap on the tank should help clean up the engine bay.

The rear O2 sensors are for monitoring only, not feedback. You can tune them out of the PCM.

yep, but it depends on Ref,some may asked you where is your evap. my boss said, he would put a note that the EVAP is on the tank(quiet handy to work at Referee, ha)))plus i'm going to run GTO stock intake or K&N for GTO(not sure whether stock intake would fit under the hood), so removing EVAP from the front is a way to go for me..plus, no EVAP tests)))
yes, LS1 running 4 O2. Edelbrock has a holes in its headers for the front O2, so no worries there, and the stock conversion pipe after CATs should have holes as well..that's theory..as soon as i would have enough money to get all the stuff, i'll see how it goes..i suspect that conversion pipe might require some cutting to fit
as for the rest, it seems so..my engine does not use EGR, and came with all engine sensors, so i just missed an air pump, and O2 (and MAF would be within intake)...i'll see where the air pump must be, and see if its fits there, if not i'll ask my boss...
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yeah, i bought mine cheaper too, but they cut out the connectoron the harness, so now i have to find new harness for the tank and the harness that goes inside the car, more work for me..
If you tune rear O2 out, the monitors for CATs would complete and if you leave them out, you might fail Referee inspection. but of course, if you are not after the BAR label, then you can do whatever you want)))

VetteC5RFrEak
but before you swap the tank, consider that 4th gen is an OBDII, so it would have a purge and vent solenoids for the evap, and it would run different test on the evap system..
are you planning on running your stock computer?i'm not sure whether it would work or not with a stock computer..i'm doing OBDII upgrade

What do you mean by "stock" computer? Personally, I'm running a "stock" 2000 SS LS1 PCM, but the purge and tank pressure have also been programmed out. That was before I planned on using a 4th gen tank (2001), so I might be putting them back in.

I have the luxury of doing a non-emissions swap, but for emissions-legal, I'd think you'd have to do a 4th gen tank - or, at the very least, it would be a lot easier. Also, for emissions-legal, you'd have to have the rear O2 sensors - basically, you can't program anything out.

lucky you)
by stock i meant as in no emissions stuff out) ABS can be, but not emissoins..
4th gen tank will make things easier, but you still would have to figure out how to connect your stock lines to the quick connectors on the tank..I modifies all lines..here's some pictures(no fuel filter's pictures, next time)I used compression fittings...




my friend modified a/c housing, so it clears the coils now)

I didn't think that a Californian LS1 swap was possible!! You would only need the emissions equipment for the year of the car your swapping into, right?

No, you need the emissions equipment from the engine year you are using.

Its very possible my friend! All you need is the emissions stuff. Cant take short cuts on these swaps. I had fun with mine. Took me 3 times to pass the cali inspection. All because of a pin hole leak on the exhaust. Got to love those O2 sensors

I would think it would be easier to pass Californian inspection with a LS1 swap than an older style engine swap, even though it would be more expensive the way CA emission standards are headed it probably would be the smart thing to do if you plan on keeping your third gen long term.