Getting ready to pull the 4.3 out of my 96 Blazer and was wondering who had replaced their oil pump and with what brand. Good or bad I would like to know. I found several posts saying stay away from the Melling brand. Anyone have a preferred brand and why? Is there really any need of going with a higher volume pump? If so please explain why. It just seems that unless I change the oil pan to a higher volume one I might run into a dry pan problem.

 

I am not sure about brands, but no need to go higher volume, the one that is in there is enough

 

Wow,thats odd as in my early years as a small block builder:Melling was always a first choice! Wouldn't know what to recommend at this point then. Do NOT go with a high volume pump in a stock "W" 4.3! These engines were generally machined well enough to allow 5w-30 oil to maintain a 40psi at idle with 100k. My 211k 97 runs well above 40 at idle and close to 60 at speed,even hot. The logic is that if you have a larger sump(pan) one needs a higher volume pump to push the oil to the valvetrain in very high RPM situations.If you don't have a high-performance built unit all you will realize is higher oil pressure but less actual lasting lubrication in upper engine areas. I have a built 68 Corvette 350 in my 66 C-10-running a stock Melling pump-almost 100k on this engine and still delivers the pressure designed for those motors:18-25 at idle and just under 40 at speed.

 

Yup, this! I even remove the oil remote filter on my first gen, reading that people experienced loss of oil pressure slightly, and I have not noticed a drop, so the OEM one is jusssst fine.

 

Also,not knowing why your replacing it,i just wanted to leave in a fun fact.

Pumps is not the reason for oil pressure to drop (90% of the time)

oil pressure is created from the tight tolerances in the bearings system. worn bearings? lack of oil pressure when hot? usually time to rebuild. Pumps job is to pump oil. thats it