Engine tuning help please

I recently did a 6 to V-8 conversion on my 66 mustang. I dropped in a 302, 285hp crate engine from the Engine Factory. My problem is when the engine warms up, approximately 5 or more miles, and I get in to it a little it bogs down like its starving for fuel. It also tends to run a little rougher at idle and sometimes dies when at a stop. No problems at all when cold. I've already replaced the fuel lines with 3/8 alum. tubing and routed it away from any heat sources. The engine is timed at 12 deg BTDC at idle and unvacuumed, increasing to about 38 deg BTCD at 3500 rpm and vacuumed. The engines specifics are 302 ci, roller cam, edelbrock 650 cfm 4 bbl on eldelbrock performer dual plane intake. HEI electronic ignition, high flow GTP Ford iron heads (sometimes called P heads), Stans headers into 3" dual exhaust with H pipe and flowmaster mufflers. It has a C-4 automatic into a 9" ford rearend with 3:50 gears. Any suggestions will be greatly appreciated as I've come to a roadblock as what to try next. I really thought a had a fuel line problem after reading several previous posts on this forum.
 
Sounds like a nice setup, should scream, I had a torque converter in a C4
do just that. When it wormed up it would lock up to fast and stall the motor at idle and have no performance. When I kicked it to the floor the engine would bawg down like a fuel or ignition problem. With that seup you need a 2500 stall. Then the FUN begins.
 
Lafayette? I'm just up the road in Opelousas. Just me but, all my Holley carbs have had the choke assemblies removed, you just don't need them here. Even on the coldest mornings, I usually just have to baby the motor a few minutes to get it idling. Otherwise they just fire right up and idle on their own.