## How do I know what length push rods I need?

The machinist’s ball should measure 0.3125-inch in diameter. Place the ball in the cup and measure the overall length including the ball. Then subtract half the ball diameter (0.1562-inch) to get the overall length. As an example, if the pushrod measures 7.6562 0.1562 = 7.500 inches.

Does pushrod length affect valve lift?

While you may not think that pushrod length affects the overall valve lift – it does. In a stud-mounted rocker system, the length of the pushrod alters where the rocker arm contacts the valve stem.

### What diameter pushrods do I need?

When to Go Big: Choosing Pushrod Diameter and Wall Thickness

Pushrod Diameter x Wall Thickness (inches) End Style (degrees) Length (inches)
5/16 x 0.080 180 Ball 5.85 – 11.050
5/16 x 0.105 210 Ball 7.00 – 9.650
3/8 x 0.080 210 Ball 6.00 – 12.250
3/8 x 0.135 210 Ball 7.00 – 10.175

The baseline run was made with 7.400-inch, . 080-inch wall pushrods, and the 383 made 515 horsepower and 490 lb-ft of torque. Jumping up to the 7.450-inch pushrods, the dyno graph shows an increase on the top end of the graph, with a slight loss compared to the 7.400-inch pushrods below 5,800 rpm.

#### How do you measure pushrod length with shaft rockers?

Place an adjustable checking pushrod into the lifter and install one intake and one exhaust rocker arm assembly. Be sure the cam is rotated to the base circle. Insert a feeler gauge on the valve side of the rocker arm to set your desired lash. Use the adjustment on the pushrod to determine the correct pushrod length.

What happens with too much lifter preload?

and keep the valves open when they should be closed. Or, as engine rpm increases, the bleed down rate inside the lifters may be too great. If this happens, then there will not be enough time to refill with oil between each valve cycle, causing the lifter to collapse.

## What diameter are LS pushrods?

LS Hardened Chrome-Moly Pushrods (3/8″ Diameter, . 135″ wall) – Cam Motion.