Like I used to tell my high school students- - - - -"Make it stop and steer before you make it go fast". Those heavy duty drive axle were never intended to run the speeds you're proposing, so even if you do manage to modify the 302 for the RPM capability you're considering, the drive train will either hand grenade itself or wear out parts that can never be replaced. Good luck- - - - -you're going to need it.
Jerry
Jerry my interests are to keep it @ or below 55mph. Which is about top speed for stock on these trucks my viking can run highways all day long, just looking to build more power out of the engine so i dont have to work it as hard when pulling a load.
The real question is where can information on coleman 4wd conversions be found. Like service manuals. Currently flying blind & would like to find information to study up on. Google wasnt much help it shows me coleman grills and anything that has nothing to do with my gmc making it difficult to research lol.
