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Well, now that I've got the Mass-Flo EFI system running pretty well on my car (1968 Mustang) I've noticed that the oil pressure gauge indicated the pressure is running higher than it used to. It's not a numbered indicator, but rather an arc with an "L" at one end and an "H" at the other. Before the engine work, if the arc was numbered by % with "L" being 0 and "H" being 100, it would run somewhere around 60%. Now it seems that when the car runs it is somewhere around 80%. Other than the Mass-Flo EFI system, of which the only things that touch the engine are the new intake manifold and distributor, I changed the heads to AFR 165 head w/ pedestal mount rockers, and I put on Scorpion 1.7 roller rockers. None of the internal engine stuff (pistons, rods, oil pump) was touched. Just a head swap and then the EFI system was put on. I put 4.5 qts of 10W-30 in, plus a quart of the Lucas oil additive, and am using a Motorcraft FL-1A oil filter. Chris at Mass-Flo was a bit stumped, and so am I. Any suggestions? Also, what are there any dangers of driving the car if the oil pressure is actually as high as the guage indicates, and if so, what are they?
 

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You engine is probably burning cleaner and better. Did you change pushrods? Some have smaller holes that restriction oil to the roller arms and give a higher PSI? Actually only thing is that you pump driveshaft better be a good one, you maybe got something in the oil pan while changing the heads out and now it's in the pumps relief valve, sticking it.
 

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First of all don't put a lot of faith on that factory guage. At best they are only an indicator. Install another independent gauge with actual psi readings on it and verify your suspicions with the pressure. Just a suggestion.
 

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Buy or borrow a good, accurate mechanical gauge and check the actual pressure. The old rule of thumb was to have about 10# pressure for every 1,000 RPM. With modern oils snd the right bearing clearances, you need less. Excess pressure can lead to a twisted-in-half oil pump driveshaft or, worse, wornout or stripped gear teeth on the cam or distributor. Too much pressure also can overheat the oil which may lead to foaming and loss of good lubrication. It also takes extra power, wasting fuel.
 
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