Melling oil pump specs
There are 7 (so far) ls oil pumps for ls engines. They are all wet sump so that makes classification easy and universal use for gen3 on4.
M295 - std pressure std volume rotor thickness .420"
10295 - 10psi higher pressure std volume rotor thickness .420" hardcoat anodized includes std pressure spring also
M295HV - 10psi higher pressure 18% more volume rotor thickness .499 includes std pressure spring
10296 - 10psi higher pressure 18% more volume rotor thickness .499 hardcoat anodized includes std pressure spring
M355 - 25psi higher pressure 33% more volume rotor thickness .507 does not include std pressure spring
10355 - 25psi higher pressure 33% more volume rotor thickness .507 hardcoat anodized includes std pressure spring
M365 - 15psi higher pressure 33% more volume rotor thickness .507 does not include std pressure spring
The M355 is std equipment for vvt and afm engines. M365 is std equipment for vvt, afm, and hybrid engines.
I will be updating this thread with block and body measurements as well later.
Hopefully that is better info to make a good decision.

