oil pressure on stock 5.0
 

Ques on oil pressure on a stock 5.0. Stock gauge will read about 1/2 when cold at idle or under load. Once warm, the gauge reads 1/2 when driving, but when at idle, gauge will drop down to about 1/4. (2nd line from the bottom i believe.) Is this normal? I know the stock gauges are sh*t, just wanted some input. This is the case with my 90Gt, as well as a friends 91 GT conv. Thanks.

No that is not normal. I would check with a mechanical oil pressure gauge for sure.

My oil pressure gauge now stands a bit over 1/2 all the time after installing a new crank, bearings and oil pump. It used to read 1/4 at idle and 1/2 under load, and although some of the bearings didn't look too good it never knocked or anything. I'd say it's normal. If you look at a chiltons book it says something like 40-60 psi at 2000 rpm. If you're getting down to 15 psi or so at idle your engine might be getting worn on the bottom end.
If you're concerned you can always add "liquid bearings" :D (15W40 oil or 20W50 oil) to take up the clearances a bit and get pressure back up.

My gauge stays around the halfway mark, but when I hit 5th gear it drops off some:confused: . It has done this ever since I can remember. I know the guage is pretty useless but am not sure why it only changes in 5th gear.

Re: oil pressure on stock 5.0
 

Yes, it is normal. When I used to work for Ford and a car would come in for a low oil pressure, Ford says to check pressure with a mechincal guage and check. Just because the needle was low did not indicate the oil pressure was dangerously low. If it is in the "normal" range then you were OK. It sucks, but what you going to do. You should check the oil pressure with a mechincal one to make sure. Technically all you need is 10 psi of oil pressure per 1,000 rpms . I still would not feel comfortable with less then 20 psi at idle. If it is lower then that, you can also get a thicker oil.

Now that I think about it, I believe it was 1991 was the first year they came out with the guages having "normal" written in the guages. I could be wrong but don't remember. Your second line would be the "n" on normal on the newer cars. That's one of the reasons why they had "normal" written on the guages. To many compliants about "this being to high" or "to low", etc, etc.

how much does a mechanical gauge cost?

Mine's a 90 and it has normal written on the gauge.