I'm having a conversation with someone about the feasibility of pulling 3V heads off a 2005 4.6L, and putting on 2V heads. Why? Because the 3V heads have been disappointing compared to the 2V in terms of reliability — chewed through timing chain guides, valve lash adjusters going bad, and probably more issues on the way (a little over 150K miles). Conversely, the old 2V engines don't make as much power but they seem to go forever without issue. I'd probably drop a 2V in the car in if I...

3V engine with 2V heads?