I recently bought a very rust free 1996 Thunderbird lx 4.6. I know the engine is in good condition for up at 180k the transmission is a little worse for wear. And the interior seems to be kinda the worst thing, but not biggest concern. But I have been trying to haveing a stable argument with my family weather I want to stick with stock engine or swap. First, I live in NY and we have strict laws on everything. I have to run 02 sensors and cats, so no carburetors. I think a cam and head swap would be the best. I have heard my best option is to go with a 01 to 03 pi mustang heads. I Have searched for new heads and trick flow seems to be the only ones that work with a 1996. So my big question why is all new cylinder heads on performance sights saying they only fit a 1999 to 2004 mustang. But, some advice would be great with how many difference are in the 1995 to 1999 engines. And what works after market and not.