5.0 engine...

I love my 5.0. Welcome back.

I would recommend you look up the GT40P head swap (explorer/mountaineer). Also the aftermarket aluminum offerings. In a perfect world, you'd buy an explorer engine from a junkyard, swap over your mustang stuff like distributor, oil pan, different cam, etc, and drop the new motor in. If your current 5.0 is running decently enough to drive as-is for a while, i'd recommend trying to source an explorer motor and rebuilt that. Then the mustang has alot less downtime.

I bought an explorer motor with a cracked block from an explorer that had been in an accident for $350. I swapped the heads and intake onto my stock bottom end with it in the car. What i learned was PULL THE MOTOR. By the time i have gotten that deep into it, all i'd have to is pull the motor mount and bellhousing and she'd be out, and I wouldnt have to droop over the fenders so damn much. I did it, its done, it runs, but goddamn if i wouldnt have paid an extra $300 for a better engine, just so i couldve done it RIGHT the FIRST time.

$500 seems to be the magic number for engines around here. I was going to go the explorer motor route, but they told me I could buy the heads and intake off of one for $300 total. Add in the money to rebuild my bottom end and seal it all up with fresh gaskets and im at around $700. It makes more sence to me to pay $700 for a leak free, fresh built GT40 motor than $500 for an explorer motor that I have no idea what condition the internals are in.

172K on a 5.0, your probably going to want to do gaskes, rings and bearings anyway while its out.

If the motor is not burning oil and feels strong, I would throw the typical bolt ons and enjoy it for a while. Headers, full exhaust, gears, maf, tb, bump the timing. Then if you catch the performance bug, you could change the heads, cam, and intake all at once and start making bigger power