So I'm trying to do some homework on a build before I pull the trigger. I'm trying to LS3 swap my 08 GS350. So I'm wondering how much power the GS 8spd(460) and 6spd(350) can handle. I'd like to keep a Lexus transmission as they are smoother shifting. I know I'm gonna have to find someone to fabricate an adapter for the bell housing. Anybody have any info on this? I've scoured google but to no avail. Any help would be appreciated

 

Lexus trans ECU wont respond to the LS3 so the work to make it function with the LS3 seems overkill. Why not just do a 480le for the LS? You are already removing the engine and size wise a 4L80E or 4l60E GM transmission is similar to the stock one in the lexus. If you truly have the fabrication and mechanical knowhow to do an engine swap on a Lexus i dont think you would be asking on this forum which transmission is best. There is a guy who put a smallblock into his is350 on the IS forums and think that would be your best place to start. Also how are you going to Fuel this LS3, you'll need AN fitting and lines and a much bigger fuel pump, a PDM to power the new fuel pump, stand alone ECU and trans controller etc. Sounds like a rad project but you would be the first and would be manufacturing many parts and figuring it out as you go. I have an s13 with Lq9 that had a swap kit made for the car and available terminated harness and it was still a massive undertaking so good luck my friend!

 

I was trying to see if anybody had info. I figured I'd be the 1st to do it to 3rd gen GS. I'm just trying to gather as much info as possible. I wanted to try and use the stock transmission so I wouldn't have to fabricate a custom shift panel or have to reshape the tunnel. I see what you mean though about the LS3 not being able to communicate with the Lexus trans module. As for fueling, it's always a given that you have to upgrade a fuel pump/injectors for Horsepower applications so I'm not worried on that side. I'm more concerned on the wiring aspect of stuff. I suck at doing electrical. I'm thinking about reaching out to Sikky to see if they can make me a kit. I have seen that build. The white IS350 with the LS1. I'll try to look for his build thread, hopefully it's still there. I dont know how to fabricate and my mechanical skills go as far as replacing motor/transmissions. I dont rebuild or overhaul transmissions or motors. I know that its gonna be alot of fab work which I'm probably gonna have to outsource to someone else. I want to do as much of it as I possibly can but I know my limits as well. I appreciate the help.

 

Is350 ls swap