Okay, sorry for the long delay, been busy. Here's my full rundown;
2007 LX470, stock. 287,XXX miles when the exhaust was installed. As I mentioned it was pretty challenging due to lack of clearance, you have to disconnect the motor mounts and jack the engine up a few inches (watch the fan / shroud and coolant T's when you do this). I used new OEM studs and nuts and the DT gaskets, I read later that I should've used the Toyota gaskets so I'll probably go back in next year and change them.
We did the headers on 8/6/2020 then on 8/14/2020 I took the car to Red Run Exhaust in Ephrata PA and they did a full header back system. They did new cats, 2.5in from the headers into a big Magnaflow, then 3in from the muffler into a resonator then out the side corner. I had them point it out of the corner because I hated having exhaust blowing on me if I was standing in the back loading / unloading.
Headers shipped from DT - $875
Studs and nuts - $100
Red Run Exhaust - $691
I do a lot of driving in my vehicles and I drive my car pretty aggressively. I'll say that the power improvement was VERY impressive, definitely surprising and borderline shocking. My wife who DDs it often (she really doesn't care about cars or performance) called me in disbelief at how fast it was. How many HP gain? I don't know, a significant amount to get this big monster up and going as quick as it did. I'm very impressed with the headers and the performance from them and would do this again.
