PML Valve Covers for Chevrolet® 396, 427, 454, & 502 Big Block Engines, CHEVROLET Script, Tall

Part Number 9739

Dimensions: Click here for dimensions. A separate window will open. Please check for clearance issues with firewalls, brake bosters, alternator, air conditioning brackets, and the like.

Finishes: Read about finishes and construction of PML parts.

These tall heavy duty valve covers from PML for big block Chevy engines feature raised CHEVROLET script and fins and top quality construction. The classic CHEVROLET script is licensed from General Motors.

Benefits of these PML valve covers:

• PCV and oil fill/breather holes
• Holes have internal baffles cast to reduce oil blow-by
• Thick walls and gasket flanges for strength and a secure seal to the cylinder head
• Sand cast construction for an old-school look and feel

PML designed these valve covers using original GM cast iron heads. Chevrolet Big block engines include: 396, 427, 454, and the 502.

These valve covers are a bit taller than stock to fit over many roller rockers. Always verify clearance before ordering. Using double gaskets to add height frequently causes leaks. Customers have reported to us that PML tall valve covers eliminated the need for double gaskets and the leaks.

For our standard height Chevy big block valve covers, see PML Part Number 9737.

Breather and PCV Holes

PML Chevy big block valve covers have PCV and oil fill/breather holes and baffles cast into the covers. The internal baffles help prevent oil blow-by out the PCV and breather holes.

These holes work with standard 1 1/4 inch grommets.

If desired, a breather cap with a 1 inch outer diameter tube can be used with the breather grommet.

Close up view showing that the PML Big Block Chevy valve cover has a good fit with grommet and chrome push-in breather cap installed   PML Big Block Chevy valve cover, breather grommet, and chrome breather cap   PML Big Block Chevy valve cover, breather grommet and chrome breather cap installed, top view
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Checking Clearance

Click for dimensions.

Engine configurations vary so please check for clearance for larger valve covers. The walls and gasket flange are thicker than stock and the fins and script add height to the top.

Look for clearance on the inside also, especially if you have roller rockers. A simple check can be made if you have the stock valve cover. Set the stock cover on the head and measure the distance, if any, between the gasket flange surface and the head. Our cover is approximately 3/8 to 1/2 inch taller than the stock cover. PML tall covers are approximately 3/8 inch taller than our standard height covers.

Some customers have reported that their roller rockers contact the inside of these PML valve covers at corners. PML has heard that grinding a bit off the roller rockers on #1 intake and #6 intake, one intake rocker on each side of engine, can add enough clearance (but this is not something we have tried or endorse).

Inside of Valve Covers

These valve covers have an open interior without oil drippers so that there is clearance for many roller rocker systems.

The baffle is cast into the covers. (It is the square feature between the bolt holes.)

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Flyer

Click to view or print PML Big Block Valve Covers PDF Flyer. A separate window will open and load the pdf file.

PML Valve Covers Compared to Stock

  
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These images show a PML valve cover compared to the stock cover. The outside dimensions are shown. The distance to the gasket surface maybe different. See the link below the "Buy Now" button for more information on dimensions.

Installations

Our thanks to our customers who have shared pictures of their installations.

Super Chevy Magazine chose these tall height PML Big Block Valve Covers for their 1967 Chevelle build. See their on-line article: Roller vs. Flat Tappet Cams

283 Grind Thumpr Comp Cams

Mike purchased PML valve covers for his big block engine on his 1930 Ford Coupe street rod. He also upgraded his Cam and roller rockers. His cam is a 283 grind Thumpr from Comp Cams and the roller rockers are a generic kind, gold in color and very squared off. He used a standard gaskets, not extra thick.

To get the PML covers to fit, he rounded off the left side corners on two of the roller rockers. The valve covers fit great after grinding a bit off the roller rockers on #1 intake and #6 intake (one intake rocker on each side of engine). He did not remove any material from the valve covers. He was told later by an engine machinist that this procedure is virtually always necessary when you try to put roller rockers on a big block chevy.

502 Engine

PML polish finish valve covers installed on a Chevy 502 engine.

Thank you to our customer Jeff for providing the picture.

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Vintage Hydroplane, Miss Merion Bluegrass

Kirk installed PML valve covers on his Vintage Hydroplane, Miss Merion Bluegrass. Miss Merion Bluegrass has a 427 engine, Hilborn fuel injection and Dart Heads.

  
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1955 Belair

Tim Ruddick of Texas installed PML tall big block Chevy valve covers on his 1955 Belair with a 454 engine. He emailed us to let us know that the covers fit perfectly and he had at least an inch of firewall clearance. He also said "I think they look awesome and went well with the old school theme in my engine compartment. The quality, fit and finish were first rate." Thank you Tim for sharing your pictures and letting us know.
   
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1955 Chevrolet with 540 Engine

John installed PML's tall big block valve covers on his 1955 Chevrolet with a 540 cu in engine. The covers have the polish finish. John also installed a PML transmission pan on his Chevy.

1955 Chevy 210 Sedan

We saw Shawn Fetter's beautiful 210 Sedan at the Grand National Roadster Show in January 2018. It won the Outstanding Overall Award in the Competiton Vehicle class. We'd like to think our valve covers had something to do with that!

   
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1957 Bel Air

Lance dressed up his 1957 Bel Air 496 big block with these PML valve covers. The engine features Pro Comp heads, roller cam and rockers, and .621 valve lift with 1.72 rocker arms. The engine is moved forward 1.75 inch.

1957 Bel Air, 496 Big Block   Pro Comp .621 valve lift with 1.72 rocker arms   PML valve cover on passenger side of 496 engine   PML valve cover on driver side of engine, 1957 Bel Air, 496 Chevy Big Block
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1965 Impala

Richard just finished his 1965 Impala SS with a 496 stroker when he sent us these pictures. His email noted that the engine got several compliments at the Impala's first car show.

1965 Impala SS   Stock valve covers on the Impala   Driver side of the 1965 Impala SS 496 stroker engine, PML valve covers installed PML valve covers installed, passenger side view, 1965 Impala SS
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1970 Chevelle SS

Billy installed these valve covers on his 1970 Chevy Chevelle SS with a 396 big block. He also purchase PML gaskets to go with the valve covers. The cast finish covers look great with the orange engine block and cast intake manifold.

     
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1972 Chevy Truck

Jeff chose PML tall height big block valve covers in the orange powder coat finish for his 1972 Chevy pick up truck.

He purchased RM Specialties wire looms and oval shaped the holes with a dremel tool. The fit around the hole on the PML valve covers was too tight for the wire looms to work without modification. PML does not recommend grinding on the valve covers. Removing material from wire looms to fit the valve covers is usually a better option.

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PML Valve Cover Features

• Strong sand-cast aluminum construction
• Thick side walls and gasket flanges that will not bend when bolts are tightened
• Cast-in internal baffles
• Mounting hardware included

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Learn more about finishes and construction of PML parts.

General Motors Trademarks are used under license to PML, Inc.