I'm not sure you are going to be competitive with you dad's Daytona Coupe, but here is what I would suggest in order of how I would approach it (I have posted this before in another thread).
1. Monty Carlo Bar and Export Brace - These are cheap, easy modifications that can be done in an afternoon and will box in the engine compartment and help to stiffen up the front end.
2. Upgrade to a 1" Front Sway Bar - another cheap, easy mod, that makes a noticable difference.
3. Upgrade your shocks, front and rear - KYB's if your on a budget, otherwise get Edelbrock IAS or Koni. Here is no place to save money, buy the best that you can afford.
4. 620 Front Springs and the Shelby drop - Upgrade to some aftermarket
Upper Control Arms if your budget allows, either OpenTracker, Global West or TCP and increase the Shelby drop to 1-3/4" (recommended). The springs are cheap and the drop is free.
5. Adjust your rear ride height with some lowering blocks to match your new front end - cheap, almost free.
6. Now get some quality tires. If you don't already have them, get at least some 15" wheels, 225/50/15's will make a great tire. If you want and can afford, go ahead and go for some 17" with 235/40/17 front and 255/40/17 rear. Good quality tires are the biggest improvement that you can make to handling and stopping power of your car.
7. Add some subframe connectors - This is a crucial step in stiffing up the unibody chassis of a Mustang and will really help in the handling of the back end of the car.
8. Now is the time to upgrade your rear springs - I suggest 4.5, mid-eye leaf springs (you can fine adjust the mid-eyes with lowering blocks if you need). Also, add a quality shackle kit at this time to help control difflection.
The above recommendations will get your car set up pretty well and if you get into it further, consider:
Front
Suspension
- Roller Bearing
Lower Control Arms (OpenTracker, Global West or TCP)
- Adjustable Strut Rods ( StreetOrTrack, Global West or TCP)
- Roller Spring Perchs (OpenTracker)
Rear
Suspension
- Maier
Panhard Bar
- Traction Master underrider traction bars (upgraded with AFCO Springrods)
Good luck and keep us posted,
Tim