What oil are you guys running in your /6?

I just put filled the engine in my 1965 Barracuda with New Holland 15W-40 (similar to Ambra 15W-40) that I've had for a while. For more pressure, I replaced the stock pressure relief valve spring with a hemi spring. Other than the cam and a 4bbl carb, my engine is stock. Since I'm running about 60 psi at idle and 75-80 psi fully warmed-up above idle with this oil, I'll switch to a 10W-30 Heavy Duty Engine Oil for my next oil change since HDEOs already have plenty of zddp built-in. I'll probably use a PetroCanada Duron-E then.