I've never said that HV pumps are bad. Just use them in the applications that require their use. If you have a healthy engine with the bearing clearance in the .0003 inch range that GM recommends. After all. Their the ones that designed the 403, and 455. And they did a real good job. Time has proved that. The 455 that I'm working on now . Seems to have been well done. I've heard that some people put in HV pump as a preventative measure for the wear that will occur later. If done correctly at rebuild time. Most of us won't live long enough to see that day. As your bearing should never touch the crank. And the HV pump didn't save this 455. It's simple. Enough oil wasn't getting to the crankshaft bearings. And I will figure out what happened. The evidence, and story is there. We all make changes to our GMC's to improve what ever, as we see it. It's how we enjoy these things. It's a hobby for many. I get the change in the final drive ratio's, fuel injection, air bags, and that list goes on, and on for ever. And we have great vendors that enjoy our money too. ( GRIN ) The thing is that GM put in our engines the pump that they thought would do the job they wanted done. In the case of my GMC. That stock pump as done the job it was designed for. For 38 years. And a 154,000 miles. I just see no mistake to fix there. I'm not saying that anyone is wrong. The reasons that I seem to hear are ones that seem to come from opinions. I would just like to see some data that the designers at GM overlooked something. The dialog has been great. But it usually is here. Thanks to all. And you never guessed that I love talking power plants. There's always something out there new to learn about.
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