I have recently purchased an 1946 Olds 98 Custom Cruiser. She has been customized with a lot of upgrades, but she is an uncompleted basket case.

She has been upgraded to 4 wheel vented discs with a dual master cylinder located under the drivers seat. The check valve barb on the MC accepts an 3/8" hose. Can I use an 3/8 rubber fuel line to run the approximate 4 feet to my connection on the intake manifold or do I need something more substantial?

 

There are no "hoses" on the master cylinder. I ASSUME you are talking about the rubber vacuum hose that supplies vacuum to the brake power booster. If so, then fuel hose is the correct material to use.

 

Basket case, so no hoses to the brake power booster. I figured fuel line would work, but had concerns about the length, all that vacuum created by the 257 flathead 8 . This is my first vintage car with the luxury of power brakes. I'm used to 80 year old drum brakes.
Thank you for your help.

 

If the vacuum were strong enough to collapse the tube, it wouldn't matter if it were 4ft long or 4in long. If you are really concerned, just run hard line for most of the length and use fuel hose at the ends.

 

You must be able to buy vacuum hose by the foot surely?.

Roger.

 

I used fuel injector line on mine with no issues.