Umbrella Seals, Nylon w/ Viton Insert

3/8" Heavy Duty Small OD Umbrella Seals, fits inside some dual springs

Fitment: BB Chevy, FE Ford and other universal Apps

Purchase is for 8 Seals.

For a 8 cyl engine, order quantity of two.

These small OD 3/8" umbrella seals are next to extinct!

Once specially made for General Motors, they have since been discontinued.

These small OD seals were used in their high performance 454 & 502 big block engines running dual springs. They were the final umbrella seal design used before GM went to all positive seals to meet lower emission requirements.

Part# VSS-313 is the smallest OD 3/8" big block seal ever available to us, they fit over stock OD BBC guides (.625") and will also work on FE Ford with guides up to .660" outside diameter.

The material is hard nylon with a viton grommet/insert. The viton insert really improves its ease of installation and seal. Unlike solid nylon seals where some oil still passes between the seal and stem, the viton insert seals completely in this area.

This type of seal will not hardenen and break apart like other umbrella materials. The nylon body is already hard as manufactured and will not disintegrate and it is much more tolerant with rubbing against springs/guides than soft rubber materials.

The best feature is the seals have a very long life and frequently can be re-used even after significant milage.

     Specification Data:

• Fits: 3/8" Valve Stems.
• Inside Diameter, smallest point: .682”
• Outside Diameter, widest point: .760”
• Height: .665” Tall
• Depth of ID- .500"
  
• Seal Material: Nylon w/ Viton Grommet
  
• Material Temp Rating: 450F
• Seal Type: Heavy Duty Umbrella
• Part # VSS-313
  
• Number of seals included in purchase:Eight Seals