Just finished installing new thorley headers on my 94 pu 22re took it out wheeling went to thomas mountain in anza out to cranston juction on the south trail noticed alittle more power at the lower end and just alittle better mpg. There was alittle increase in the in cab noise but not much. Hope to see more when I get the money for 2.25" high flow cat & muffler & pipe. But till then every bit helps. The WEATHER OUT HERE IN SO CAL IS GREAT IT IS COOL FOR A CHANGE!!!!!