Kurgan sold a couple of 03 Cobras making over 600 rwhp for under $30k last year. One was 26k if I remember correctly. With $14k more, I could get over 900 rwhp. You think that a 430 rwhp S13 LS1 could hang with that?
Mustangs are pretty much the cheapest platform that you can get to go fast. That's why they are popular.
Take a 92 S13 and spend 10k on it. You will always be slower than a 92 Mustang with 10k dropped in it.
Sold my '03 Cobra pushing 656rwhp for just under $20,000 about a year ago.