Center section of manifold cracking..

[marek4792]

It started around this time last year possibly earlier when the mpg dropped off, it still had the mandate Uni and you had tweaked and RR's tune with stock 565/1850 fueling, would randomly blow out the turbo flange gasket found the flange itself was cracking on the oem manifolds tried the aftermarket one and same deal except it did on both sides of the turbo flange at the 90° bends
Always installed to spec and slip joints lubed with light film of antiseize. Cac was replaced at that time too. The white smoke on start up was around that time when I chose to inframe it due to oil consumption and cooling system starting to pressurize. Been running it across the RPM band 14-2000 rpm with varying loads. Based on this the injector is the only variable we hadn't messed with. Either going to cap each cylinder until I find the offending ones or just do a 6 pack and do the break in overhead. I'll update when I know meanwhile I'll get the file sent to you, I agree this is very odd.