This is a basic idea of what I'd build if I had the money for another car...
89 white coupe, 10 holes - BFG DR's, black trim, red interior w/ cheap seats
Lentech'd AOD w/ converter - stock shifter
351 w/ junkyard twin turbo system
3.27 gears
Small(er) camshaft
Bigger heads like AFR 205s or Vic Jrs
Sheet metal upper w/ TFS 351 lower
Dynomax Muffs w/ tailpipes
Through the floor subframe connectors
Stock ride height w/ adjustable struts and Wolfe-like rear anti-sway bar
Big fuel system
If money allowed, DFI
Pro's:
1. Big motor that is stronger than roller 302 w/o the expense of going to an A4/R based stroker.
2. Turbo - a) the most efficient power adder w/ the added benefit of helping to eliminate the exhaust noise b) they like the small cams, ie no rumpity rump
3. Gears - 3.27's don't shout, "hey, I have lower gears than stock", yet work well at allowing for 130+ mph trap speeds w/o spinning the engine to the moon
4. Outward appearance could look and sound factory stock
5. 550+ rwhp capable
Con's:
1. One may not have access to the tools necessary to fab the turbo system and upper intake
2. May be able to see intercooler from outside the car
3. To be most effective, the chassis would need to be stiffened further
4. Underhood would hardly look stock
5. Emissions compliance
6. The converter would give a hint the car wasn't stock
7. Hooking it up
It could all be done for less than $10k, maybe as low as $8k if one had hookups.