DT header Upgrade
Shortly after I purchased mine in the summer of 2018 with 235K the HG let go and thus a rebuild was in order. So I installed MLS gaskets lapped the deck and heads and loaded the heads with ARP head studs. Putting in a set of DT headers and punching out the exhaust to 2-1/2"...
DT header Upgrade
Pitch the OEM exhaust and put a Doug Thorley Header on it. That is what I did and it makes the assembly much easier when it is bellhousing to engine joining time.
Open Loop Vs Closed Loop Running
I know your pain. Is there any change after its warmed up? The thermistor in the back manifold tells the ECM when it's time to start looking at the O2, knock and AFM with TPS. If you have coolant leaking the sensor may be in an air bubble?
