heres the parts list i followed for my swap, got it all to the T. made the swap easy not having to stop to run to auto zone.
Parts Checklist:
01+ PI Romeo Heads with Cams – 1W7Z-6049-AA (RH) and 1W7Z-6049-AA (LH) (1 each)
01+ PI Intake Manifold Assembly – 1W7Z-9424-AB – (1 assembly)
99+ PI Cams - 1L2Z-6250-AA (RH) and 1L2Z-6250-DA (LH) - (1 each)
01+ PI Head Gaskets – 4C2Z-6051-AA (RH) and 4C2Z-6051-BA (LH) – (1 each)
01+ PI Intake Gasket – YL3Z-9439-BA -(1 each for a total of 2) – or Fel Pro – MS-92121
01+ Cam/Valve Cover Gaskets – F6AZ-6584-AA (RH) and F6AZ-6584-BA (LH) – (1 each)
New OEM Head Bolts – 5R3Z-6065-AA -(20 bolts)
Alternator Bracket - F8AZ-10153-EA – 96-98 with PI Intake/Al. Crossover - (1 bracket)
Coolant Tube – XR3Z-18B402-AA - (1 tube)
Coolant Nipple – F75Z-8555-AA – (1 nipple)
Timing Cover/Front Cover Gasket – F1AZ-6020-A – (1 gasket)
Timing Cover/Front Cover Gasket – F1AZ-6020-C – (1 gasket)
Timing Cover/Front Cover Gasket – F6AZ-6020-BB – (1 gasket)
Exhaust Manifold Gaskets – YC2Z-9448-A - (4 gaskets)
Crankshaft Seal – F5AZ-6700-A – (1 seal)
Crankshaft Bolt – F5RZ-6A340-B aka: F1AZ-6A340-A – (1 bolt) or ARP-156-2501
Camshaft Bolts – YF7Z-6279-AA - (1 for each cam for a total of 2 bolts/10mm bolts)
OEM Dipstick or Lokar Oil Dipstick - XR3Z-6754-BA or LOK-ED-5014 – (1 dipstick)
Upper Plenum O-Ring – XR3Z-9L437-BA – (1 o-ring)
Thermostat O-Ring – F1VY-8255-A – (1 o-ring)
Water Pump O-Ring – F1VY-8507-A – (1 o-ring)
Header Down-Pipe Gasket – XR3Z-9450-AA – (1 gasket)
Stock or 180* Thermostat – 3L3Z-8575-AC (192*) or XL3Z-8575-AA (180*) - (1 t-stat)
Spark Plug Wires – F8PZ-12259-HA – (1 kit) – You do not need the wires, it is just an extra.
i cant take credit for making this list, it was a very old post on modulardepot.com
i HIGHLY reccomend the Lokar dipstick and Stage 8 locking header bolts. together its another 100 bucks, but man is it worth it.
when you get to putting a new dipstick in, you will see why a flexible one is worth the 60 dollars. and when you drive it for a bit and get an exhaust leak, you'll see why a set of 30 dollar bolts and collars are worth it.
i did a friend's PI swap, and he went all stock parts, we wasted alot of time trying to get the dipstick to line up without pinching it, ended up pinching it and rounding it back out with pliers to get it in. and he had an exhaust leak from the passenger side after a couple heat cycles, he ended up taking it to a shop.
i did mine, the lokar goes in in literally 5 seconds, just put some sealant on it, stick it in the block and go. more than enough play to work with. and it looks good. and the Stage 8's, put them on, tighten good, put the collars on so they back up against the primaries and cant get loose, never had a leak, not even a slight one.
hope this helps