How To: Check 302/351 Mustang Pushrod Length

Pushrod Length Checking Kit

Checking push rod length is extremely important when building an engine. If this step is overlooked, and is taken for granted, serious damage can occur to your valve train components. Things you’ll need before checking push rod length is obviously your short block, cylinder head, head gasket, roller rockers, and a dog bone or lifter retainer. Throw in our special push rod length checking kit, digital, or dial caliper. I can’t stress enough how important this step is when assembling your engine. NEVER take it for granted, and always, always check for proper push rod length.

Required Tools

• Socket Set
• Socket Wrench
• Engine Oil
• Permanent Marker or Paint Pen
• Assembly Lubricant
• Digital or Dial Caliper

Installation

1. Apply a small amount of oil to the lifters.
2. Install the lifters into the engine block with the holes facing up and toward the center of the engine.
3. Position one of the lifter retainers between the lifters in their marked orientation.
4. These are also referred to as ‘dog bones’.
5. Position your head gasket and cylinder head.
6. Whatever cylinder you’re working on, snug down the four cylinder head bolts or studs surrounding that particular cylinder.
7. Or whichever method you prefer to hold down the head while you turn the engine over.
8. Grab your Trick Flow push rod length checking tool and remove the two stop nuts.
9. Screw the two ends back together and set the push rod length tool to the factory length of 6.272 inches.
10. Color the top of the valve with a permanent marker or paint pen.
11. Slide the tool through the guide plates.
12. Position one roller rocker onto the guide plate and push rods length tool.
13. Tighten your roller rocker set screw to zero lash.
14. Zero lash is achieved when you can just barely turn the pushrod with your hands.
15. Make two full rotations and return the key-way to the twelve o’clock position.
16. Notice the valve tip sweet from the roller on the rocker arm.
17. Grab your caliper and measure the width of the valve tip sweep.

- The ideal width for a street application is eighty thousandths. - Seventy to ninety-five thousandths is allowable. - If for some reason you are not within the allowable numbers, contact your local machine shop to help you purchase the correct length push rod for your application.

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