Which is the best to put in a 4.9 six cylinder ford engine high volume oil pump or regular?

For a Ford 4.9L inline-six (often found in trucks and Broncos), a high-volume oil pump is generally only recommended if you're significantly increasing engine RPM or have modifications that increase oil demand. This includes things like forced induction (turbocharging or supercharging), high-lift camshafts, or other performance upgrades that put extra stress on the lubrication system.

A standard-volume oil pump is perfectly adequate for a stock or mildly modified 4.9L. A high-volume pump, while potentially beneficial in high-performance situations, might actually be detrimental in a stock engine. Here's why:

* Excessive pressure: A high-volume pump can create excessive oil pressure, potentially leading to seal leaks and premature wear on components not designed for that pressure.

* Increased load on the oil pump: It requires more power to drive a high-volume pump, slightly reducing engine efficiency.

* Unnecessary expense: Unless you're modifying the engine for significantly increased performance, the added cost of a high-volume pump isn't justified.

In short: Stick with the standard-volume oil pump unless you have specific performance modifications that necessitate a high-volume pump. If you're unsure, consult with a mechanic specializing in Ford engines. They can assess your specific setup and advise you on the best choice.