Overheating issues!

[94GTMustang5.0]

89 LX, 5.0

Problem: Overheating.

description: Car will run fine for about 10 minutes, takes forever to heat up, then once it heats up it wont cool back down. will stay at 3/4 of gauge and wont get any hotter unless i drive it hard. Once it hits 3/4, it starts to run like dog poo. Coolant is vanishing, no visible leaks. No coolant in oil. Large amount of pressure building in the cooling system.

New parts:

Radiator
Water pump
180 degree t-stat
Thermostat housing

What I think: Bad head gasket? On startup, small puffs of white smoke from both tailpipes. small drops of water from exhaust. After running the car for about 10 mins and driving around the block, water droplets and smoke go away.

 

[BYRDPE]

89 LX, 5.0

Problem: Overheating.

description: Car will run fine for about 10 minutes, takes forever to heat up, then once it heats up it wont cool back down. will stay at 3/4 of gauge and wont get any hotter unless i drive it hard. Once it hits 3/4, it starts to run like dog poo. Coolant is vanishing, no visible leaks. No coolant in oil. Large amount of pressure building in the cooling system.

New parts:

Radiator
Water pump
180 degree t-stat
Thermostat housing

What I think: Bad head gasket? On startup, small puffs of white smoke from both tailpipes. small drops of water from exhaust. After running the car for about 10 mins and driving around the block, water droplets and smoke go away.

you have some classic symptoms of a blown head gasket.

 

[Dino Dino Bambino]

Large amount of pressure building in the cooling system.

What I think: Bad head gasket? On startup, small puffs of white smoke from both tailpipes. small drops of water from exhaust. After running the car for about 10 mins and driving around the block, water droplets and smoke go away.

Puffs of white smoke from a cold start on a cold, damp morning would be normal but if you're getting them on every start up combined with overpressurization of the cooling system, I'd say it's odds on you have a leaking head gasket.
Pull the plugs and inspect them. Any that are either wet or washed with coolant will give the game away.