On the Thorley header they use a 3/8 flange where LCE uses a 1/2 flange. I thought I had read something about the thicker flanges lasting longer. And some Thorley flanges warping. If your running the Thorley header what do you think of them? Any issues?
Everyone has a different opinion. Doug Thorley has been manufacturing headers since 1958. If a 3/8" header flange was warping, they would have fixed it back in 1958.
I've had 3 Toyota 22R/RE trucks with DT headers and they performed great.
I use only the DT header gasket from Doug Thorley.
I DO NOT use the self-clamping style header nuts!!
I torque the hex nuts to 25 ft lbs.
I check and retorque the header nuts every couple days until they stay torqued. Some times that takes several hundred miles.
That's just my limited experience.