[86-C10-V6]

Unless you are running a race car, you are much better off with the Qjet than the Holley or the 1406.
Edelbrock's 1904 Qjet is designed by the same engineers that designed the Qjet that was placed on you truck from the factory.
The Qjet provides better all around performance and does not require a lot of tuning, just tune the idle mixture and you are done. The Qjet will normally provide both good gas mileage and good performance.
You can tune the carb for more power, it just takes more knowledge and time. There are several web sites with a lot of information on how to tune the 1904 for performance.
You can not tune a worn out carb, and they do have wear issues that can only be addressed by remanufacturing. Rebuilding a worn out carb will not gain you anything.
If your carb is the orginal, I would highly recommend a new edelbrock 1904 as a replacement.
This is just my opinion.