Ive got a 90 mustang gt I just put a new 306 and t5 swap , The problem is the car is spewing coolant past the radiator cap and filling the resevoir and overflowing, This is my 11th mustang and Ive never come across this before, Heres what the car has done 4 core jegs rad., two electric fans, new water pump, new 16lb cap, new 160 thermostat, new water pump hoses , old radiator hoses swelling under pressure,Under drve pulleys, short belt bypassing smog pump, Car reads 150 - 170 degrees on autometer gauge The car had this problem before swap but not as noticeable, In my opinion the fans are 2 small, the radiator could use flushed, the cap may be 2 short or not strong enough , any help greatly appreciated, THANKS