You need a bullet proof botom end and with probably a power adder without having huge cubes..

What do you condsider bullet proof?

All that would be needed, is a stock bottom end with ARP fasterners and maybe even a Main Girdle. Keep the rpms under 6,300 rpms with balanced parts.

A set of AFR 185 or Twisted Wedge Heads, custom ground cam or an extreme energy grind cam from comp-cam. Depending on induction a 650 mighty demon carb with a Victor jr intake, Or a Holley system max intake, edelbrock rpm II, or even a TFS intake would work.

A set of full length headers and 2.5-3.0 exhaust.
3.73-4.10 gears.
That basic combo on a 3,200 pound car, that hooked, would easily run 11's in a 5-speed car.
As goes for a power adder...150 shot would result in a low 11 or high 10 second time slip and do-able with $10,000. I would just keep it in the 11's, if longevity is a factor and tune-up ...right!

If a bullet proof bottom end is in order, then run the most amount of cubes you can. That means 418+ cubes,...if it's not going to be in a cubic inch limit class. (minimal amount of difference in cost at the bottom of that wish list) Just beware that it will easily be over $10,000 at that point.
My .02's

Size doesnt matter im gonna use it for driving/ beating street racers into the ground.

Pull out $20,000-$30,000+

Dart block with the 4.125 bore option
4.0 stroke or 4.100 stroke. 428-434+ cubes
6.200 h-beam rods
-21cc////-24cc's dish piston. (10 to 1 --- 10.5 to 1 compression)
Get a 4340 forged steel kit from Scat or Eagle with H-beam Rods.

TFS-R or 225 AFR heads (minimal work)

Super Victor Intake (stock)

825 Mighty Demon Carb

Kook Headers 1 7/8 headers w/ 3.0 inch exhaust

C-4 or a Tremic tko-600 trans.

3.73 Gears.

Complete Aeromotive Fuel Sysytem from front to back.

Hyd roller cam in the 250 range at .50 on the intake side. Shift the car around 6,000 rpms.

That will be enough to run in the mid 10's on PUMP GAS without a poweradder!!!! Hit it with a Wilson Plate in the 200-250 range and run in the low 9's! (conservitive)*
*will require a pro-shifted trans or a full race built C-4.

Good Luck and remember, there will always be someone faster then you.

They're right, I have $10,300 in my N/A 331. That's not counting the Turbo kit yet.

$10k is a nice start and foundation to build on.

I also agree with buying the already done mustang, there is nothing like building it yourself beleive me, but if you don't have the time, then take your time buying a nice one.