[leftybass209]

I doubt it needs to be said, but road course/autocross and pickup truck are kind of oxymorons.

As such, if this is for anything other than fun, the prebuilt chassis are really the only way to be competitive, considering how far the other vehicles in the field have come.

That being said, the cheaper option will probably give you the most bang for your buck, and the more expensive options may have the law of diminishing returns playing against them.

Think of it like sound deadening. Covering 25% of a panel will give you the most benefit for the cheapest amount. Adding more sound deadening is adding significantly more cost vs reward at that point.

Adding a frame stiffener on a stock chassis makes a massive difference. A more expensive option may have calculated the absolute best weight, material, balance, and stiffness, which may gain you a small amount of benefit. However, you're still limited to that stock chassis and all of its drawbacks to begin with, versus a better-suited chassis option.