Oil Pressure Relief Valve, Heavier Spring Useful?

[Douglas Morris <dcmdcm@earthlink.net>]

While thumbing through catalogs, I saw a stiffer spring option for the oil
pressure relief valve.

Questions: 
- How much of an increase in normal oil pressure does this option provide?
- Are there any drawbacks?
- Is that increased pressure useful when the existing oil pressure is near
the low spec limit? (No, I haven't checked-out the oil pump yet, but I
will.)

DougM (NC)
74TR6 CF18310OU