Mopar Magnum Pushrods Buying Guide
TL;DR: Pushrods are the one valvetrain part on a 5.2L or 5.9L Magnum that cannot be ordered off a catalogue listing alone. Correct length is a number you measure on your own assembled short block with a checking pushrod, because it changes the moment you swap heads, mill a deck, change gaskets, change lifters or change rockers. Once you know the length, the remaining decisions — wall thickness, material, tip style and construction — follow from how much spring pressure and rpm the engine will actually see. Buy the set that matches the measurement and the spring load, not the set with the biggest advertised number.
Why the Magnum Is Its Own Valvetrain, Not a Warmed-Over LA
The Magnum is Chrysler's 1992-through-2003 revision of the LA small block, sold as the 5.2L (318) and 5.9L (360) in Ram trucks, vans, Durangos and Dakotas. It is a cast iron, overhead-valve pushrod V8, so it uses lifters, pushrods and rocker arms in the conventional American V8 arrangement.
What trips people up is the assumption that LA parts simply carry over. They do not, and the valvetrain is exactly where the two families part company. The LA small block used shaft-mounted rocker arms. The Magnum abandoned the shafts and mounts its rockers individually on pedestals bolted to the head, and it moved to a factory hydraulic roller lifter arrangement retained by a spider and yokes rather than the LA's flat tappets.
Those two changes move the geometry. A different rocker mounting arrangement and a different lifter body mean a different pushrod length, and a pushrod that is correct for a 360 LA is not automatically correct for a 360 Magnum. Confirm the current part number for your exact combination against the manufacturer catalogue rather than assuming a generic Mopar small block listing covers both. Platform hardware is grouped under Mopar LA and Magnum small block parts, and the rods themselves sit in pushrods.
Length Is Measured, Never Guessed
This is the single most important idea in the guide, so it gets its own section.
A pushrod's job is to hold the rocker tip in the correct arc across the valve stem tip, and to give the hydraulic lifter the right amount of plunger preload at the bottom of that arc. Both of those are geometry, and geometry is set by the stack of parts under the rocker. Every one of the following changes it:
- A cylinder head swap, or heads that have been surfaced
- A block deck that has been milled
- A head gasket of a different compressed thickness
- Aftermarket lifters with a different pushrod seat height than factory
- Aftermarket rockers, especially a roller rocker with a different ratio or a different stand height
- Valves of a different installed height, or valve seats that have been cut deeply
- A camshaft with a base circle that differs from stock
Any one of those is enough to make the stock length wrong. Two or three of them together and you are guaranteed to be wrong.
The method is straightforward. Assemble the engine as it will run — real head gasket torqued down, real lifters, real valves and springs, real rockers — then install an adjustable checking pushrod on one intake and one exhaust with that lifter on the cam's base circle. Lengthen or shorten the checking rod until the rocker tip sweeps a narrow, centered pattern across the valve tip through the full lift event, and until the lifter is sitting at the preload the lifter or cam manufacturer specifies for that part. Measure the checking rod, then order to that measured length.
Check both an intake and an exhaust. On many engines the two are not the same length, and on a head that has been reworked they can diverge further. Checking pushrods, dial indicators and the rest of the measuring hardware live under engine stands and tools.
Wall Thickness, Diameter and Material
Once length is known, the rest of the specification is a load question. A pushrod fails by bending, not by pulling apart, and bending resistance comes from outside diameter first and wall thickness second.
| Consideration | Stock and mild builds | Higher spring load, higher rpm |
|---|---|---|
| Wall thickness | Thinner wall is adequate; it is what the factory geometry was designed around | Thicker wall resists flex under heavier spring pressure |
| Outside diameter | Stock diameter clears the head's pushrod passages without modification | A larger diameter may require the pushrod holes in the head to be clearanced |
| Material | Standard steel is fine for stock valve springs and stock rpm | Heat-treated chromoly is the normal step up for aggressive cams and stiff springs |
| Construction | Pressed-in ends are entirely adequate at stock loads | One-piece or heavy-wall designs are preferred where flex is a real concern |
| Oiling path | Follow the design the engine was built around; do not mix conventions | Same rule — the lifter and rocker design dictates this, not preference |
The practical guidance for a Magnum: if the engine keeps its factory-style springs and factory rpm range, a stock-replacement pushrod in the correct measured length is the right part, and spending more buys nothing you can measure. If the build has a substantially larger cam and the spring pressure that goes with it, step up to a heat-treated chromoly rod with a thicker wall, and check clearance through the head's pushrod passages before final assembly. A rod that touches the head at high lift will wear a groove into itself and eventually fail.
If you are moving to a larger outside diameter, confirm passage clearance by hand-turning the assembled engine through at least two full revolutions and inspecting for witness marks. That check takes ten minutes and prevents a dropped valve.
Tip Style, Hardening and the Parts Around It
Pushrod ends come in ball and cup arrangements to suit the lifter seat and the rocker's pushrod socket. Match what your lifters and rockers actually use rather than what a generic listing shows. When you change rocker arms — a common Magnum upgrade, since the factory stamped pedestal rockers are a limiting part on a built engine — verify the rocker's pushrod socket style against the pushrod you are ordering. Rocker options and trunnion hardware are under rocker arms and trunnions.
Hardened tips matter most where a guide plate is in use. If your setup runs guide plates, the pushrod must be hardened at the point of contact or the plate will saw through it. If there are no guide plates, a non-hardened tip is acceptable, though there is no penalty in running hardened anyway.
Finally, treat the pushrod as one part of a set. Lifters, pushrods, rockers and springs are a system, and the failure people describe as "the pushrod bent" almost always started somewhere else — a collapsed lifter, coil-bound springs, a rocker with the wrong ratio, or simply a rod that was never the right length. Lifter options sit under lifters, and the rest of the valve gear is grouped under valves and valvetrain.
A Short Buying Checklist
- Assemble the engine as it will run, with the correct gasket and the correct lifters.
- Measure intake and exhaust length independently with an adjustable checking pushrod, on base circle.
- Set the sweep pattern narrow and centered on the valve tip, and confirm the lifter preload the manufacturer specifies.
- Choose wall thickness and material from spring load and rpm, not from marketing.
- Match end style to the actual lifters and rockers you are installing.
- Verify head passage clearance if the diameter changed, by turning the engine over by hand.
- Torque all valvetrain hardware in the factory sequence to the values in the service manual for your engine.
- Confirm the current part number against the manufacturer catalogue before ordering.
Frequently Asked Questions
Are LA and Magnum pushrods the same? No. The Magnum uses pedestal-mounted rockers and a factory hydraulic roller lifter arrangement, while the LA used shaft-mounted rockers and flat tappets. The geometry differs, so the pushrod length differs. Verify the correct part for your specific engine family against the manufacturer catalogue.
Do I really need to measure, or can I just order the stock length? If the engine is genuinely stock — original heads, original gasket thickness, unmilled deck, factory lifters and rockers — a stock-replacement length is usually correct. Any deviation from that list means you measure. Measuring costs one checking pushrod; guessing costs a valvetrain.
What happens if the pushrod is too short? The lifter plunger sits with too little preload, the rocker sweep shifts toward one edge of the valve tip, and the valvetrain gets noisy. Too little preload also allows the plunger to travel to the limit of its stroke and clatter.
What happens if it is too long? Excess preload holds the valve slightly off its seat, which costs compression, burns exhaust valves and can bend parts. It also pushes the rocker sweep to the opposite edge of the valve tip and loads the valve guide sideways.
Do I need hardened pushrods on a Magnum? Only guide plates make hardened tips mandatory. Without guide plates a standard tip is acceptable, but hardened costs little and does no harm.
Can I reuse the original pushrods after a cam swap? Only after you measure. A camshaft with a different base circle diameter changes the required length directly, and any head or gasket change stacks on top of that.
Should I replace pushrods and lifters together? Yes when the lifters are being replaced anyway, and always if a lifter has failed. A failed lifter usually damages the mating pushrod end, and a worn end destroys the new lifter seat.
Sources
Consulted for this article: Chrysler service manual practice for the 1992-2003 Magnum 5.2L and 5.9L small block; general pushrod length-checking and valvetrain geometry procedure as published by valvetrain component manufacturers; Core Powertrain Parts internal fitment notes for Mopar LA and Magnum applications. Specific torque values, preload figures and part numbers should be confirmed against the manufacturer catalogue and the service manual for your exact engine.
Questions on a Magnum valvetrain combination? Email sales@coretransmissionparts.com. Free shipping on orders over $70.