What's your budget? An M1, some decent mid-length headers, and a cam, along with SCT to reprogram the PCM (total investment ~$1200 total, will net you an easy 100hp.

Those mods on my 318 Dakota had it running mid 14 sec 1/4 miles (with 2.3 sec 60' times due to slippery street tires...with traction, low 14s were possible.

Those same mods with a 5.9 has my truck now running low 14s, and still traction limited.