PCV Hose Identification

The BOSS 302 engine has a crankcase ventilation hose commonly known as the Positive Crankcase Ventilation (PCV) hose. The hose routes from a metal tube on the plastic spacer assembled under the carburetor (shown below) to a right angled block on top of the PCV valve mounted in a grommet at the rear of the right valve cover.

Carb Spacer

PCV hose routing

PCV hose at valve cover

Note the bumpy, "alligator skin" look of the hose above and below. This is not a soft sponge rubber hose. It is stiff and internally reinforced which gives it this look. Also note the yellow stripes and markings. These appear to be manufacturer's markings as they are not shown on the Ford drawing.

Real BOSS 302 PCV hose

Above photo courtesy of Tim Barker

The engineering part number is C9ZE-6853-B.

Hose - Crankcase Ventilation

The service part number is, hmmm, well let's take a look at the 1975 version of the Ford Parts Catalog (a.k.a. the Master Parts Catalog (MPC)). Base part number -6853- is in section 60.5 for the eight cylinder 302 and 302 Special (BOSS) engines on page 16. Service part number, uh-oh, it says, "Cut to fit from bulk hose 4090", and "Also refer to group 6A664".

1975 MPC base 6853

Ok, go back, -6A664- is on page 14. Here are some service part numbers, C9PZ-6A664-A and C9PZ-6A664-B. Under Quantity 302 Spec it says, "AR" (which means As Required). Under the description for C9PZ-6A664-A it says, '15/32" I.D. - 25 ft. long-cut as required' and for C9PZ-6A664-B it says, '5/8" I.D. - 25 ft. long-cut as required'.

1975 MPC base 6A664

This sounds like bulk hose on a reel. Wait, there is no exact service replacement for the BOSS 302 PCV hose?

Yes, it appears Ford never released an exact service replacement part for the BOSS 302 PCV hose. It also seems to be the case for the base 302 engine as well. How often do you think a PCV hose failed? It was probably more "efficient" for Ford to have the dealers cut a stock bulk hose than to have to release and track service parts for all of these odd shaped hoses that would probably never wear out especially on a low volume engine like the BOSS 302. There are no NOS service BOSS 302 PCV hoses. This is why an original hose is so hard to find.

If you need a PCV hose what are your options?

1) Find an original hose.

2) Find some C9PZ-6A664-A (Ford Motorcraft KCV-1) or C9PZ-6A664-B (Ford Motorcraft KCV-2) bulk hose. However the inner diameter for C9PZ-6A664-B seems too big.

3) Go aftermarket bulk hose. You can find cross references to other hose manufacturers' part numbers on the internet. Gates, NAPA, Goodyear, Dayco, etc. The Gates 27005 might be the best option for a fiber reinforced hose with acceptable inner diameter.

4) Try your favorite Mustang parts supplier. For years there has been a "BOSS 302 PCV hose" available from the Mustang parts suppliers. Unfortunately this hose was not 100% like the original. It has a right angle bend and is about the right length. However it is not marked like an original hose. Nothing in yellow. Where did they get that part number? It is also a soft sponge rubber and is known to collapse in on itself when the engine is running.

Bad aftermarket hose 1

Bad aftermarket hose 2

It does appear though as of this writing (April 2023) there may be a new reproduction reinforced hose available from Mustang parts vendors. Maybe we are getting closer to a like-original part.