Tools

ProForm Camshaft Checking Tool: Accurate For Cam Setup

The ProForm Camshaft Checking Tool for accurate lobe height. Essential for engine builders and performance enthusiasts

Todd Bandel

30 Jul 2026 • 9 min read

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Getting a camshaft right isn't about trusting the cam card blindly-it's about verifying every lobe before the engine goes together. The ProForm camshaft checking tool gives builders a reliable way to measure what actually matters, directly from the block, without guesswork or improvised setups.

Quick Overview: What the ProForm Camshaft Checking Tool Does

The ProForm camshaft checking tool is a dial indicator-based fixture that slides into the engine block's lifter bore to measure cam lobe lift and base circle runout. It's built primarily for Mopar B/RB and Hemi V8 applications, though ProForm offers models covering GM and Ford platforms as well.

ProForm's lineup includes two key part numbers:

66843 - A dial indicator lobe checker designed for Chrysler 273–440 and Hemi engines, with followers sized for 0.904 in (flat tappet/hydraulic) and 1.000 in (roller) lifter bore diameters.
66838 - A camshaft checking fixture and cam bearing service kit tailored to GM lifter bores (0.842 in) and Ford bores (0.875 in), bundled with an arbor, drive spools, stabilizers, and a drive cap.

ProForm ‎PFM66843 Camshaft Checking Tool

Dial Indicator, 0 to 1.000 in, 0.001 Increments, Hydraulic/Roller Tappet, Mopar B/RB-Series, Each. Check the camshaft with precision using this reliable tool, perfect for DIY projects.

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The 66843 kit includes:

A 0–1.000 in travel dial indicator with 0.001 in increments
Two interchangeable followers for flat tappet and roller cams
An expanding O-ring mount that locks into the lifter bore

ProForm tools include a 0.001 in dial indicator, and the tool provides accurate measurements of camshaft specifications during engine assembly. It eliminates guesswork by providing repeatable measurements directly from the camshaft, which means you can verify cam card specs-advertised lift and duration at a given rocker ratio-without fully assembling the valvetrain.

A Proform camshaft checking tool measures camshaft lobe lift and base circle runout, making it useful for diagnosing suspected camshaft wear and checking after machining or rebuilding. Proform tools are also designed to verify lift and timing characteristics of an unknown camshaft, which comes up more often than you'd think with vintage Mopar builds where paperwork has been lost.

Typical buyers include performance street builders, bracket racers, and engine shops wanting to confirm camshaft quality before final assembly. Camshaft checking tools help ensure proper timing critical for high-performance engines, and catching a problem at the mock-up stage saves hours of teardown later.

ProForm tools use aluminum and steel construction-lightweight enough to store in a toolbox, durable enough for repeated shop use. Compared to improvising with magnetic bases and generic indicator mounts, a dedicated ProForm camshaft checking tool delivers repeatable accuracy and faster setup every time.

Key Features and Specifications of ProForm Camshaft Checking Tools

This section breaks down the feature set of the ProForm 66843 dial indicator cam checker and the closely related 66838 camshaft checking fixture, covering the details that matter when you're deciding which kits to add to your shop.

Dial Indicator

The indicator face is easy to read whether you're standing over the block or working at arm's length. Some users in review feedback have noted that the stock indicator works well out of the box, though a few builders prefer to swap in a higher-grade unit for critical race engine work.

Followers and Tappet Contact

Two followers are included for flat and roller cams:

Flat tappet / hydraulic follower - 0.904 in diameter, matching standard Mopar B/RB bores
Roller follower - 1.000 in diameter for roller cam setups

Using the correct follower diameter simulates real-world lifter contact on the lobe, which matters because contact geometry directly affects measured lift. ProForm camshaft checking tools support both flat-tappet and roller camshafts with interchangeable followers, so you don't need separate kits for different cam types. ProForm cam checker tools support flat and roller cams without any modification.

Lifter-Bore Mounting System

The Cam Checker Tool adjusts securely in the lifter bore through an O-ring expansion system:

The tool body slides into the bore and expands to lock in place
Heavy-duty O-rings on both ends center the fixture and prevent lateral movement
This rigid mounting eliminates the vibration and drift common with magnetic-base setups

ProForm tools are designed for optimizing camshaft performance, and solid bore mounting is a major reason the readings stay consistent across multiple checks.

Construction and Dimensions

Lightweight aluminum body with anodized or natural finish
Steel posts, fasteners, and indicator stems for rigidity
Approximate size: 11.5 x 5.5 x 1.8 in
Weight: approximately 1.33 lb

ProForm 66838 Camshaft Checking Fixture

0.001 in Dial Indicator, Flat/Hydraulic Camshaft Followers, Aluminum, Natural, Kit

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Summit Racing Equipment

ProForm 66838 Cam Bearing Fixture

The 66838 is a complementary tool that pairs well with the dial indicator checker. It includes an arbor with drive mount, two drive spools, two spool stabilizers, and a drive cap-everything needed for removing and installing cam bearings while keeping them aligned in the cam tunnel.

ProForm 66838 features a 0.001 in dial indicator as well, and it has earned a solid 4.4 out of 5-star rating from roughly 97 customer reviews. Together, these two tools cover inspection and installation in a single workflow.

Pricing and Availability

Street price for the 66843 generally falls in the $90–$110 range, making it an affordable option compared to professional-grade metrology fixtures.
Available from major retailers; most orders ship quickly with standard and expedited options.
The 66838 is similarly priced and often shown alongside the 66843 in retailer recommendations.

Many retailers allow customers to submit a review or email feedback on product descriptions, which helps keep pricing competitive and specs accurately listed. If you spot a lower price elsewhere, some vendors will match it. For reference, you can also find builder walk-through videos online demonstrating setup and use on various engine platforms.

How to Use a ProForm Camshaft Checking Tool for Accurate Results

This section walks through a practical procedure for using the ProForm camshaft checking tool on a Mopar B/RB V8 or similar pushrod engine. ProForm cam checker tools are easy to install and use, but following a consistent process matters for accuracy.

Preparation

Mount the engine on a stand with the intake manifold removed for clear access to every lifter bore.
Install the camshaft, timing set, and degree wheel on the crankshaft
Establish true top dead center (TDC) for the number-one cylinder using a piston stop-errors here will shift every reading downstream

Installing the Cam Checking Tool

Select the correct follower: flat tappet for solid or hydraulic cams, roller for roller cams.
Slide the tool body into the number-one intake lifter bore
Expand the O-ring mount so the fixture locks squarely with zero side-to-side play

If you feel any wobble or tilt after seating the tool, remove it, inspect the O-rings, and re-seat. Even minor misalignment introduces cosine error that compounds across multiple lobes.

Dial Indicator Setup and Zeroing

Position the dial indicator plunger so it runs straight along the axis of lifter travel.
Rotate the crankshaft by hand until the follower rests on the base circle (no lift)
Set the indicator to zero.
Rotate through a full engine revolution and confirm the needle returns to zero at base circle.

Checking Cam Lobe Lift

Rotate the crank slowly to maximum lift and record the peak reading-this is your measured lobe lift.
Calculate valve lift: multiply lobe lift by your rocker arm ratio (1.5:1 stock Mopar, 1.6:1 for many aftermarket roller rockers)
Compare the result against the cam card specification

A deviation greater than 0.005–0.010 in may indicate an incorrect cam grind, machining tolerance issues, or valvetrain geometry problems that need to be worked through before final assembly.

Measuring Base-Circle Runout

With the indicator zeroed on base circle, slowly rotate the crank while watching for any needle drift.
Repeat across several lobes to confirm lift consistency
Excessive variation or "egg-shaped" readings on any lobe may warrant camshaft replacement before buttoning up the engine

Camshaft checking tools help optimize camshaft performance by catching these issues early, and precision measurements with a camshaft checking tool improve reliability and power output once the engine is running.

Practical Tips and Safety

Always rotate the crankshaft by hand-never use power tools with the indicator installed.
Keep metal chips, solvent, and debris away from the indicator face and followers.
Store the tool in its case after every use to protect precision surfaces
Inspect O-rings before each session; brittle or worn rings compromise mounting security

Frequently Asked Questions

What is the Proform Cam Checker Tools 66838?

The Proform Cam Checker Tools 66838 (PRO-66838) is a precision camshaft measurement tool designed to accurately measure lobe lift and base circle runout directly from the lifter bore — without removing the camshaft from the engine.

The tool slides down into the lifter bore and rests atop the camshaft lobe, delivering precise dial indicator readings for engine builders and performance tuners who need verified cam specs during a build or teardown.

What is the Summit Racing part number for the Proform Cam Checker Tool 66838?

The Summit Racing part number for this tool is PRO-66838, assigned by the manufacturer Proform.

When ordering or searching, use PRO-66838 to ensure you are purchasing the correct Cam Checker kit. It is sold as a complete kit and is listed under Proform's line of engine measurement and valvetrain tools.

What does the Proform Cam Checker Tool kit include?

The Proform Cam Checker Tools 66838 kit includes:

One dial indicator for precise measurement readout
One flat tappet/hydraulic cam follower for use with flat tappet and hydraulic camshafts
One roller cam follower for use with roller camshafts

The kit provides everything needed to measure camshaft lobe lift and base circle runout without purchasing additional components separately.

What lifter bore sizes does the Proform Cam Checker Tool 66838 fit?

The Proform Cam Checker Tool 66838 fits two of the most common lifter bore diameters used in domestic V8 engines:

GM .842 in. diameter lifter bores
Ford .875 in. diameter lifter bores

This makes the PRO-66838 compatible with a wide range of popular GM and Ford engine platforms, including small block and big block applications commonly used in performance and racing builds.

How much does the Proform Cam Checker Tool 66838 cost?

The Proform Cam Checker Tool 66838 (PRO-66838) is priced at $99.99 and is sold as a complete kit. The kit includes a dial indicator and two cam followers — one for flat tappet or hydraulic cams and one for roller cams — making it a cost-effective solution for accurate in-engine camshaft measurement.

Complete Cam Service in One Setup

Combining the ProForm dial indicator cam checker (66843) with the 66838 cam bearing fixture gives engine builders a complete solution for inspecting, installing, and verifying camshafts in-house. You can remove old bearings, press in new ones with proper alignment, and then immediately check every lobe-all without moving the block off the stand.

Whether you're building a weekend cruiser 440 or blueprinting a race Hemi, the ProForm camshaft checking tool gives you confidence that every lobe is within spec before the heads go on. Pick up the 66843 for your next Mopar build, or grab the 66838 if you're working GM or Ford platforms, and take the guesswork out of cam setup for good.

Thank you for reading!

Your friend,

Todd

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