Got my 4.56 gears on!

[als]

he,s right about a thermostat. a cooler thermostat=cooler charge of air coming thru the intake manafold, because the manafold is cooler, the air is cooler and the denser the charge , that  = more h.p. so less throttle is needed to maintain speed. but there is diferrent schools of thought here some  say hotter for mpg , cooler for power. if you live in a colder climate no cooler the 180 because it will thro an engine code i.e. not warming fast enough and your heater will suck on cold days. i had this problem with the 160 thermo but the truck never knock and pinged under heavy load as it did with the stock 195, especialy if i didnt run premium fuel . now iam running a 180 with zero problems. thermostats are cheap 5-7 dollers, gaskets  99 cents or so. try a couple different ones, find what works best for you.

[SD YODA]

like als said.... the cooler the temp, the cooler the air charge (due to water running through a throttle body port) and this will make a bit of a diffrence. although i dont think his heater will be an issue as he lives in texas so i dont think he uses that much anyway  you should try it out matt, its more then likely the exra mile or 2 you are looking for. especially if you reverted back to a stock intake with a deckplate!