Sbc Motor Mount Bolt Size: A Comprehensive Guide

Motor Mount Pads Small Block Chevy SBC Sold Each CMW Trucks
Motor Mount Pads Small Block Chevy SBC Sold Each CMW Trucks from


When it comes to working on your Small Block Chevy (SBC) engine, having the right information is crucial. One of the essential details you need to know is the motor mount bolt size. In this article, we will provide you with all the necessary information about SBC motor mount bolt sizes, helping you make informed decisions for your engine projects.

What is a Motor Mount Bolt?

A motor mount bolt is a fastener that secures the motor mounts to the engine block. These bolts play a vital role in keeping the engine stable and properly aligned in the engine compartment. It is important to use the correct size of motor mount bolts to ensure a secure and safe installation.

Standard SBC Motor Mount Bolt Sizes

The standard motor mount bolt size for most Small Block Chevy engines is 3/8-16. This means that the bolt has a diameter of 3/8 inches and a thread pitch of 16 threads per inch. However, it is essential to note that there can be variations in bolt sizes depending on the specific engine model or aftermarket motor mount kit you are using.

Other Motor Mount Bolt Size Options

While 3/8-16 is the standard size, some SBC engines may require different motor mount bolt sizes. It is crucial to consult your engine’s manual or seek advice from a knowledgeable professional to determine the correct bolt size for your specific engine model.

How to Determine the Correct Bolt Size?

To determine the correct motor mount bolt size for your SBC engine, you can follow these steps:

Step 1: Consult the Engine Manual

The engine manual is the best place to start when looking for information about your engine’s motor mount bolt size. It usually provides detailed specifications and part numbers for all the components, including the bolts.

Step 2: Measure the Bolt

If you cannot find the information in the manual, you can measure the bolt yourself. Use a caliper or a measuring tape to determine the diameter and thread pitch of the bolt. Compare the measurements with standard bolt sizes to find a match.

Step 3: Seek Professional Advice

If you are unsure or unable to determine the correct bolt size, it is always a good idea to seek advice from a professional mechanic or an experienced engine builder. They have the knowledge and expertise to help you find the right bolt size for your specific engine.


Choosing the correct motor mount bolt size for your SBC engine is crucial for a secure and stable installation. While the standard size is 3/8-16, it is essential to consult your engine manual or seek professional advice to ensure the correct bolt size for your specific engine model. By using the right bolt size, you can have peace of mind knowing that your engine is properly secured and aligned, allowing for optimal performance and longevity.