O'Reilly carries a copper oil line kit with the right fitting included for $20. Made by AutoMeter if I recall.
Oil pressure gauge?
Posted 20 June 2017 - 08:37 AM
Depending on the vehicle, I usually prefer a mechanical gauge over an electronic one. Mechanical gauges don't lie, while electronic gauges can. If you have poor grounds...
A few of you have mentioned that the plastic hose on a mechanical gauge is a danger. Yes, but you can easily run steel braided line in place of it. -3 AN is as big as you need. When going through the firewall, you can use a grommet to seal it and protect it, but I like to use bulkhead fittings. Not only does this rule out any potential abrasion failure, it also makes it so that if you want to remove the gauge cluster, you can simply disconnect the hose from the fitting on the firewall (not having to mess with the fitting on the back of the gauge, which may be hard to reach).
If multiple devices are desired ie- electrical gauge sender, spray bar, low oil pressure light, mechanical gauge, etc, I run a -3 AN hose to a junction block on the fender well, and then tee off from that. I have seen many engine block mounted tees break from the weight of too many things attached to it.
If you don't want to use an adapter fitting at the block (NPT to BSPT) then you can simply tap the hole in the block to 1/8" NPT. This can even be done with a heavy coating of grease on the tap, which will catch the shavings from the block. Ideally, you would tap the hole before the engine is assembled, but in a pinch, you can do it with grease.