SBC 350 Timing Chain Kit: Which Brands Are Worth It

TL;DR: On a Gen I small block Chevy the timing set is one of the cheapest parts in the engine and one of the most expensive to get wrong, because everything it sheds ends up in the oil pan. The biggest quality divide is not the badge on the box - it is construction: a stock-style set with a nylon-faced cam sprocket and a link-belt chain versus a true double-roller set with steel sprockets. Buy on construction, stated material and the quality of the instructions, and treat a brand as worth paying for only when it publishes real specification data and an application catalogue you can cross-check. Confirm the current part number for your block, cam and cover combination against the manufacturer catalogue before ordering, and torque everything in the factory sequence to the values in the service manual.

The three kinds of SBC 350 timing set

Almost every timing set you will see for a 350 falls into one of three families. Knowing which family you are looking at tells you more than the brand does.

Stock-style replacement (link-belt chain, nylon-faced cam sprocket). This is what General Motors used in production for a long stretch of the small block's life. The cam sprocket is a sintered or cast core with a moulded nylon tooth facing, and the chain is a flat link-belt design rather than a roller chain. The nylon is there for noise: it is quiet when new and it makes the assembly line's job easy. The problem is that nylon embrittles with heat and age, and once it starts breaking away it does not stay put. It goes into the oil pan, and from there to the pickup screen. A clogged pickup on a small block stops being a timing problem and becomes a bearing problem. If you are opening the front of an older 350 and you find nylon chips in the pan, you have found the reason to do the job properly.

True double roller (roller chain, steel sprockets). Two rows of rollers on a chain running on hardened steel sprockets. It is louder than nylon, it is heavier, and it is the correct answer for almost every 350 that is going to see real use. The rollers replace sliding contact with rolling contact, which is what stretches a link-belt chain over time, and steel sprocket teeth do not shed material into the oil. Note the word true: some sets use a double-row chain on sprockets that are not fully machined steel, and some marketed as "roller" are really a hybrid. The photograph in the listing and the material callout in the specification tell you which you are looking at.

Billet true roller with a multi-keyway crank sprocket. The same idea with better material control and, usually, a crank sprocket cut with several keyways so you can advance or retard the camshaft without buying an offset key or a bushed cam sprocket. If you are installing a new camshaft, this is the set to buy. Everything you would want to do to dial the cam in is built into the part.

There is a fourth option - a gear drive - but on a street 350 it is a niche choice, it is noisy by design, and it changes how cam thrust is handled. Most builds are better served by a good roller chain.

How the families compare

Browse what is in stock under timing chains, gears and tensioners, or start from the engine and work down through SBC 350 parts.

What actually separates a good brand from a bad one

Once construction is settled, the brand question becomes answerable. These are the things worth paying for, and they are all things you can check before you buy rather than after.

Material stated honestly. A manufacturer that is proud of its sprockets tells you what they are made from and how the teeth are finished. A listing that says only "heavy duty" is telling you nothing. If the specification does not name the material, assume the cheapest option that could plausibly be described that way.

A catalogue you can cross-check. The small block Chevy ran for decades across different cam retention and cover arrangements and both flat-tappet and roller camshafts. A brand worth buying from publishes an application catalogue you can look your engine up in. Confirm the current part number against that catalogue rather than trusting a title string - this is the most common way people end up with a set that will not work with their cam or cover.

Instructions written for the part. Good sets ship with real instructions: install orientation, which timing marks to align, whether the set is ground straight-up or with built-in advance, and what to do with the keyway options. A generic photocopied sheet is a warning sign about everything else in the box.

A matched assembly. A timing set is exactly that. Mixing a sprocket from one set with a chain from another, or reusing an old crank sprocket with a new cam sprocket, defeats the point. Buy the set, install the set.

A support path that exists. If a tooth profile is wrong or a chain is out of tolerance, you want a manufacturer that will talk to you. A brand with technical support and a warranty it honours is worth a premium over a set with no identifiable manufacturer at all.

What is not a good reason to pay more: decorative finishes on parts that live inside a timing cover, and horsepower claims made for a timing set. The set's job is to hold cam timing exactly where you put it, quietly, for a long time.

Buying the rest of the job at the same time

The chain itself is a small part of the labour. Once the balancer, the front cover and usually the water pump are off, replacing the surrounding wear items costs almost nothing in extra time. Plan on the front cover gasket set, the front crankshaft seal, the oil pan front seal if your cover design requires disturbing it, and a new balancer bolt if the service manual calls for one. Those live under gaskets and seals.

Two more decisions worth making up front:

• Camshaft. If the engine has enough miles to need a timing set and you are already this far in, look hard at the cam and lifters before you close it up. Options live in camshafts, and the rest of the engine family sits under small block Chevy engine parts.
• Oil pump and pickup. If you found nylon in the pan, the pickup screen is suspect and so is everything downstream of it. Replacements are in oil pumps and pickups.

A timing set on a small block that is already out of the vehicle is a modest job. In the vehicle, with the radiator, balancer and accessories to move, most shops quote it as a several-hour job, and more in a truck with tight frame clearance. Get the quote in labour hours and ask which gaskets are included.

Installing it so the brand choice actually matters

The best set in the world will not survive a careless installation.

Clean the mating surfaces properly. The cover and block face must be clean and flat. A gouged sealing surface leaks no matter how good the gasket is.

Check the dowel and the keyway. The crank sprocket keyway and the cam dowel locate everything. Inspect both before you assemble. A sprocket that has been running loose will have left evidence.

Align the marks as your instructions define them. Do not assume the convention from another engine or another brand's set. The instructions supplied with your set define the correct alignment, including whether the set is ground straight-up.

Degree the cam if you are installing one. Timing marks get you close. A degree wheel and a dial indicator tell you where the cam actually is. This is exactly what the multi-keyway crank sprocket is for.

Torque in the factory sequence to the values in the service manual. Cam sprocket bolts, cover fasteners and the balancer bolt all have specified values and, in some cases, a specified thread treatment. Use the manual for your engine along with the manufacturer's instructions for the set. Tools for the job are under engine stands and tools.

Pre-lube and prime. Assembly lube on the chain and sprockets, and prime the oiling system before the first start. On a flat-tappet camshaft, follow the cam manufacturer's break-in procedure exactly.

Frequently Asked Questions

Is the factory nylon-faced timing set ever the right choice? Only when originality matters more than durability - a numbers-correct restoration that will see light use. For any engine that is going to be driven, a roller set is the better buy, and the price difference is small next to the labour.

Do I need a double roller if the engine is stock? You do not need it, but it is the sensible default. A stock 350 with a good roller set will hold cam timing longer and will not put nylon in the pan. The trade is a little more mechanical noise from the front of the engine.

What does a multi-keyway crank sprocket actually do? It lets you install the camshaft advanced or retarded without special tools, by choosing which keyway to use. Advancing generally favours low-end torque and retarding favours upper-rpm power, but the correct choice comes from the camshaft manufacturer's recommendation for your specific combination.

How do I know the chain is worn without pulling the cover? Often you cannot, definitively. Signals that point that way include ignition timing that wanders when checked with a light, a rattle from the front of the engine on start-up or deceleration, and rotational slack at the crank before the distributor rotor moves. An engine of rebuild age with unknown history should simply get a new set while the cover is off.

Can I reuse the crank sprocket and replace only the chain? No. The sprockets and chain wear as a matched pair, and a new chain on worn sprocket teeth wears out quickly. Timing sets are sold as sets for a reason.

Will a timing set from one brand fit any 350? No. Cam retention, cover design, cam bolt pattern and camshaft type all vary across the small block's production run. Look your specific engine and camshaft up in the manufacturer's application catalogue and confirm the current part number before you order.

Should I replace the water pump and front seal at the same time? Usually yes. They are already exposed, and the labour to come back for them later is the same labour you are paying for now.

Sources

Written from the Core Powertrain Parts technical team's bench and shop experience with Gen I small block Chevrolet engines, the general engineering principles of roller versus link-belt timing drives, and the internal Core Powertrain Parts collection and handle map used for the product links above. No torque values, capacities or part numbers are quoted here - confirm all of those against the factory service manual for your engine and the timing set manufacturer's own instructions and application catalogue.

Questions on a specific 350 combination? Email sales@coretransmissionparts.com. Orders over $70 ship free.