Want to pick y'all's brains. Just got my fresh 355 in the rig and broke in. It has a rebuilt/modified TBI unit and vortec fuel pump to support the power bump from the vortec heads, mild cam (SUM-K1102), headers etc. Ever since during break in process, I can't keep this engine cool. It will sit and idle for a while creep up. And when driving it, I can't get more than a mile before it gets to 220F+ and I have to shut it down. Even with no thermostat it gets too hot. Also worth noting that it is real sluggish when driving and occasionally surges. I've played with the timing and it seems to run best setting at about 10 deg. Advance at idle. I haven't had a chip burned yet but I don't think it would cause this many problems. Have also tried different radiators and checked that the water pump is working, fan is fine... Everything cooling related was fine with the old motor as well. So I'm thinking i have it narrowed down to intake or head gaskets? If anyone has any input I'd appreciate it.