Is it possible to swap an LS3/L99 into a Gen 4 F-body? I've seen talk about it, but I haven't actually seen a Gen. 4 with an LS3. Has anyone ever done this?

 

Yes a LS3 swap has been done numerous times on our cars

 

I wrapped this swap up in my car in May. It was straight forward for the most part. Super Chevy mag had a decent guide on the subject, all though they got some small details wrong about the vacuum lines, knock sensors, weren't detailed enough in some other areas (for instance didn't talk mention what fuel pump they were using, if you needed to upgrade it).

 

Well, that's good to hear. How difficult is it? Can you just buy and bolt on all the parts you need, or is there a lot of custom fabricating like everything else on this car?

 

With the exception of buying the lpe trigger box, the map extension harness, and the knock sensor extension harness and new knock sensors, larger throttle body everything else swaps over from the ls1.

 

Wouldn't all that stuff come with the engine? I'm just thinking about the junkyard engines that I have seen on car-part.com. Some appear to have the wiring harness and ECM with them.

My original plan was to turbo my LS1, but I'm a little concerned about fuel mileage. I'm not sure if a cammed and ported LS3 would be any better though.

 

Re-use the ls1 pcm and either swap the cam gear and crank reluctor wheel, or use the LPE trigger box. If you use the LS1 cam gear, then use an extension for the cam sensor (which is on the front of the LS3). Using the LS3 wiring harness seems like a big pain in the neck for no gain.

You canNOT use the LS3 accessories, like the water pump and balancer...

 

I was always under the impression a turbo LSX had decent mpg.

Uti, I see you finally caught that tail wind to push your car into the 12s
I guess you finally got everything sorted out on your car?

 

Yeah, I spent some money this year. The car runs great, but I lost 2 MPG across the board. That was with just bolt-ons. If I lose any more MPGs, then my HD 4x4 truck will be more efficient. That would kinda defeat the purpose of having a car in the first place. Right now, I don't have room for a third vehicle. So, buying a beater rice burner is not an option. I know I'll have to if I want my car to run 10's.

I was averaging 19-20 MPG a tank. Most of that was city driving (45mph, not many stops). Now I'm barely getting 17 MPH a tank with the same routine. My truck gets about 16 MPG on the same route. I'm not sure if it's possible to run 12's with a daily driveable car, but that's what I'm trying to do. I made one 12-second pass this year, but I had to remove the air filter to do that. I'd like to run 12's consistently without removing the air filter. I just installed a new Cat-back exhaust system with a cut-out. I'm hoping that will do the trick.

 

Yeah, I hear ya man.
Unfortunately losing mpg is a side effect if you wanna go fast. Sometimes you just have to be satisfied with what you have at the moment and plan for the future when its easier on you to mod your car again.

 

I know these motors usually come with exhaust manifolds, but I would want to run headers. Would my current Kook's Long tube headers fit/work on an LS3?

 

Yes, they will work

 

Do you have a "build thread" on here? I'm seriously considering this route instead of turbo/supercharger. I need to swap the rear-end first. That 10-bolt won't last long with anymore power. Finding a shop willing to mod my car is getting more difficult. I think I found a place to do the rear-end, but the LS3 swap might have to be a father-son project.

 

I could certainly make one, the pics are in a link in my signature. The swap has been done many times on this site.