I've been needing to do this, so here goes... oh, BTW, everything is fresh since 2002, and we've put less than 300 miles on the car in the last 2 years. Also, anything with "in progress" after it means I've already got the stuff, it's just sitting in a box or on a shelf waiting for the right time to go in/on.
(borrowing Dodgestang's very thorough and tidy model)
1970 Mustang Mach 1, purchased for $1200 in 1988 (I was 15)
Chassis/
Suspension
* shock towers replaced and reinforced (way back in 1989)
* Complete new torque boxes and floors, seam welded
* Stock upper and
lower control arms
* PST polygraphite bushings throughout
* Pro-motorsports negative wedge 1.75" A-arm drop
* stock front springs with poly insulators
* stock power steering with poly rag joint and poly idler bushing
* Monroe-matic Plus gas shocks with poly bushings
* 5 leaf mid eye drop springs with heavy duty polyurethane shackle kit
* Global West subframe connectors
* 4 wheel disc brakes, stock front, Ultrastang Lincoln Mark VII rears (in progress)
* stainless steel brake lines and hoses
* Export Brace (Monte Carlo Bar later)
* 1 Addco front sway bar
* 3/4 Addco rear sway bar
* Traction Master traction bars
Motor/Driveline
* 302
* Holley Street Dominator intake, Holley 600cfm carb
* Paxton SN60 supercharger (in progress)
* Stainless steel fuel lines
* Heddman shorty headers, 2.5" custom exhaust, X-pipe, Dynomax turbo mufflers
* AOD Transmission - stock
with homemade mounting bracket and Lokar TV cable
* Sanden compressor, 134a
* original 9 inch rear with 3.0 gears
* 3 core heavy duty radiator
* 2700 CFM electric fan with adjustable thermostat
* Pertronix Ignitor & coil
Exterior
* New quarters, wheel housings, and rear valence
*
ALL RUST REMOVED! POR15 full chasis, floors, trunk, engine compartment, and every damn other place we could spray and brush!
* New weatherstripping everywhere
* New windshield
* 1970 Mach 1 trim, hood scoop, cladding, sportlamps, pop open gas cap, etc.
* Black Mach 1 stripes (in progress)
* Front spoiler and rear wing (original)
* Lots of new chrome, still need lots more
* Hallogen headlights with relays
* Bright Gold metalic base coat/clear coat (Maaco did pretty good, but ask for the whole story)
* 15 x 7 1996 Mustang V6 machined aluminum wheels (temporary)
* 215/65/15 something or anothers
* exhaust tips hidden
* Dixco hood tach (in progress)
Interior
* Black Mach 1 interior with new headliner, dashpad, rear upholstery, and carpet (still need door panels)
* Front seats still undecided... (it was gonna be Fiero seats, then modified stock, then late model, then Recaros, now???)
* 3 point front seat belts (in progress)
* Stock guages with Dixco hood tach
* a/c
* remote driver
and passenger sideview mirrors
* lighted rearview mirror
* original console modified with cup holder (it's really pretty slick)
* intermittent wipers
with high speed wiper motor conversion
* remote electric locks
* remote electric trunk release
* cabled hood lock/release
* power antenna in stock location
* security system
* tilt steering column
* Lecarra (Shelby) 3 spoke wood steering wheel
* Aiwa indash CD/MP3 player in progress
* Alarm system with magnetic kill switch
Cost: approx. $15K, including original purchase price, 2 motors, 3 sets of wheels, and everything we've done in the last 3 years. and all the "in progress" stuff.
Performance: no numbers yet (or probably any time soon
)
What is left:
* 3.89 limited slip
* '03 Mach 1 heritage wheels
* door panels
* driving the living crap out it, everywhere, all the damn time. I'm gonna drive it 'til it breaks, then fix it and drive it some more!
I stopped counting when the shoebox with the reciepts could'nt hold anymore. 
