My Swap Plan (comments welcome)

[Shon]

I want to do a 243/Cathedral port vs a LS3/retangular port comparison but the problem is the LS3 style really needs a different cam too so then you run into lots of variables trying to compare the 2 on the dyno and track/MPH.
As I have mentioned before, 2 GTOs with nearly the same mods making nearly the same power at the wheels. 243 headed GTO was showing 2+MPH in the 1/4 on same day same track.
One thing that lots of people do not factor in with the LS3/L92 heads which Clown mentions is the intake design is different plus factor in the rocker arms that are needed, it adds into the cost if you already have cathedral heads.

Just plan it all out before you move forward but the motors can make power and useable power in all the RPM ranges.

[mcmlxix]

Also keep in mind your control system. Im looking at a 6.0L but no harness... I priced out Painless at about $1400 and Howell at about $1100. This is all new pieces, wire and delphi connectors, new TAC moduel and pedal.

If you can get the original and UNCUT harness you will be $$ ahead. You can either modify it yourself or have it done. You should also get the ECM, Pedal and TAC module from the same vehicle if possible....

[SS From the "Wood"]

So if I've got this right, a 6.0L LQ4/9 complete w/ harness, ECU, pedal, and TAC module is where I should start. Adding the L92 heads & LS3 intake, 92mm TB, and a mild cam should take care of the top end. Make a determination on accessories (Vette or Truck.) All of this should button up to a stock 4L80e, and get me to around 450+/- rwhp? Sold!

[mcmlxix]

I just got off the phone with my DMV. They require emissions equipment from the same year as the motor, not the vehicle. So I need CATs and the EVAP system to be functional...

[BR3W CITY]

do they do visual inspections?
WI has similar requirements but no visual inspection, as long as you don't throw codes, they don't care.

[52 Rat]

Originally Posted by mcmlxix

Also keep in mind your control system. Im looking at a 6.0L but no harness... I priced out Painless at about $1400 and Howell at about $1100. This is all new pieces, wire and delphi connectors, new TAC moduel and pedal.

If you can get the original and UNCUT harness you will be $$ ahead. You can either modify it yourself or have it done. You should also get the ECM, Pedal and TAC module from the same vehicle if possible....

I purchased a custom stand alone harness for my lq4 from PSI for $500. This is one awesome wiring harness! I did my research on stand alone harnesses and PSI kept coming up as one of the best stand alone LS harness builders.

http://www.psiconversion.com/

[SS From the "Wood"]

Guys & Gals,

You'll be able to follow this build in the projects/builds section soon... likely in the LSx swappers sub-forum. Thanks for all the input, but I've pretty much got my plan thus far.

-shannon

[Clownpuncher]

Originally Posted by SS From the "Wood"

So if I've got this right, a 6.0L LQ4/9 complete w/ harness, ECU, pedal, and TAC module is where I should start. Adding the L92 heads & LS3 intake, 92mm TB, and a mild cam should take care of the top end. Make a determination on accessories (Vette or Truck.) All of this should button up to a stock 4L80e, and get me to around 450+/- rwhp? Sold!

Perfect... With the right cam think closer to 475-490.

The 4l80e is a great choice let me know how she fit's. I'm in the middle of tracking down a trans with out breaking the bank. I really have a feeling Im just going to go to the yard and find a 4l65e out of a trailblazer.

From what knowledge I have of using the truck drive system is the car intake inlet will hit the alternator. It can be moved but that's another can of worms

The Vette would be a great choice but it is around $700 from GM.

It boils down to what intake you choose.

Great stuff so far