1995 K1500 header install

[Roadknee]

Primaries are too small on your headers to see any real HP gains.

This can not be any further from the truth based on the experience of professionals that make their living designing and building custom headers and exhaust systems for winning teams

There is a reason the aftermarket all use 1 5/8" or 1 3/4" primaries.

There is a reason and it's because companies are in business to sell product, and the belief of majority consumers that bigger must be better.