New (old) member here, showing off my 84 Silverado SWB

[gchemist]

K&N Web site.
Example: A 350 CID Chevy engine with a horsepower peak at 5,500 rpm.

Mininum requirement: 3.20"
Referencing the K&N catalog shows the proper filter for this application would be an E-1500 which is 3.5 inches tall. Keep in mind, this is the minimum size requirement. To extend the service interval and to provide an even greater volume of air to the engine, install the largest filter that will fit in the space allotted. If the space above the engine is restrictive, perhaps a remote filter arrangement could be used to gain space.

A 4.5 inch filter will fit under the hood!