Sorry for getting off topic. Look for a part # in addition to the msha on the nylon wrap hose. See how this one is Aeroquip 2556 in addition to the IC 84/15. Look up the hose specs and the fluid temp rating if you're using it on an oil line. You might find its max temp is very close to your oil temp.

Agree, in either case the guy I sent the hose to is replacing them all with 5/8 lines and AN10 fittings. The 1/2 fuel line started leaking oil in the bilge, and is why I started looking for the reason and found it. I removed all the lines after winterizing and sent them to be replaced. The guy I sent it to mentioned issues with to small lines prior to this thread, and is the reason for change. This thread got me real concerned about what I've been seeing and want to do whatever I need to do to save my motor before next season

My oil system was plumbed with the hose pictured with push lock fittings. That hose is rated for 212F at most iirc. Maybe I would've chanced it if it was a clamped hose.

whenever i plumb the oil lines i use -12.why not if you are replacing anyway?

Unable to say, he also is a custom motor builder and says this will work with my current components. Standard block adapter, remote adapter and cooler

Edit, just got an email, he says my cooler and stuff are smaller then 12 so that's why were using 10

how much hp you shooting for?

the smaller the hose the more restriction to flow no matter what size the cooler bungs are.

Dyno shows 530 with dry headers so I currently have around 520hp or so

I ran 509's at 650 HP with stock Merc oil lines and acc. with NO oil flow problems. This was the larger cooler ( 3 inch dia.) and hoses that come on the 502 HP.
And WHY is anyone with a non stock engine running the oil bypass. I removed, tapped and plugged mine.

ALSO
90 hrs X 50 MPH = 4500 miles
since when
most cars at 50 MPH are at 1500 RPM.
Boats cruise at 3500 RPM at 50 MPH
At 3500 a car would be at or above 100 MPH
Lets see you run your car at 3500 RPM for 90 hours and see how it lasts.

#10 line would be fine w/ a 3" cooler.what gen bbc do you have?