it depends on what mods you're going to go with. If you're going to do blower i wouldn't do it without a forged bottom end. But if you're doing small bolts on go for it.
With my 50k 2002GT i'm currently debating on a stage 1 P&P and stage 1 N/A cams so i should close to 300rwhp n/a.. hitting mid to high 12's. Right now i'm in the low 13's for sure with just all the bolt ons i've done.
Yes -- as long as you are going to keep the car. Spending a lot of money and time on mods just to get rid of the car six months later is a waste. I did that once ... never again ...
That's my problem now with the GT and Mach. You can spend a ton of money on a car you can't get much out of when you want the newest ride.
I think I'm happy for now.
I think I'll save those thousands on a ride that won't make what an 05 GT will be putting down and when the new cobra comes out it's going to blow everything away. I know me and I'm going to want a copy of one of the cars with more HP than the Mach, so time to start saving.
MY GT will be my daily driver. My Mach will be driven by my GF maybe 5 miles a day and my new BOSS or Cobra will be my new fun car. That's the plan anyway if the job hold for 2 or 3 years anyway.