So you want a 408 Stroker engine and haven’t decided to build one or buy a crate engine. Well, let’s take a look at both options.
Crate engines are easy to start with, they just cost more, but you don’t need to get dirty and don’t need to scavenge for parts. Here are tow 408 Stroker crate engine options to consider:
What is the LSX 6.0 STROKER SHORT BLOCK 408CI 9.240 DECK?
The LSX short block is an iron 6.0 block that comes with a SCAT 4340 forged steel crankshaft coupled with SCAT 4340 forged steel H beam rods. This model delivers up to 750 HP. To reach this the LSX 6.0 iron block comes with a 4.030” bore/hone with a diamond hone finish. The deck height is 9.240, and the crack is a SCAT 4340 Forged Steel 4″ stroke. This crank works with either a 24 or 58 tooth reluctor ring and has a 6 bolt flywheel.
The rods are 6.125″ SCAT 4340 Forged H beam with ARP8740 cap-screws, and the main bearings are Clevite H Series, ms2199hx with cb663hn rod bearings. The Cam Bearings are Clevite #sh814s. Other features include CP bullet series flat top 2618 forged pistons with CP rings and a steel top. You need to file fit them for your application
ATK LS01C Chevy LS 408 Stroker Complete Engine 600+ HP
The ATK LS01C gives you 600+ horsepower with 550 lb/ft of torque and uses a GM 6.0L Iron LQ4 block with a Bore/Stroke of 4.030 x 4.000. This model comes with a Manley 4340 Forged 4.000″ Stroker camshaft that is Internally Balanced with 58 Teeth. The connecting rods are Manley 4340 Forged H Beam 6.125 with ARP 8740 Bolts.
This model comes with forged pistons and has moly piston rings with a 10.3:1 Compression ratio and the camshaft design is a hydraulic roller with 240/256 @050 .625in/.625ex 113LSA.
The Camshaft Bearings are all Installed and Clocked to OEM Position, and the 68.4cc/260cc 2.16/1.59 Cylinder Heads are made from LS3 Aluminum. This model also comes with brass freeze plugs and GM Roller 1.70 ratio rocker arms.’
As you can see, two possible models that come with everything and deliver different engine performance characteristics. All you need to do is go online and search for a 408 Stroker crate engine, and you can just slip it into your car with a little help from some tools.
The other option has some fun, and build it yourself.
To do this, you need to get a “junkyard” LS engine and then search for parts. The best engine block to build up a 408 Stroker is GM’s 6.0L iron block, either the LQ9 or the LQ4. These blocks come with 4-inch factory bore, and a Gen III block is an excellent choice. You can buy them online too if you want. What you will need to do is create a 4.030-inch bore and 4.00-inch stroke. To reach this bore/stroke you can use a set of its PN K464F3 pistons, these are made from a more rugged 2618 alloy forging and come with the rings.
The next thing you should add is the connecting rods, and I chose K1 Technologies’ PN CH6125ALLB-LSL8-A that are made from 4340 forged alloy. Together with these, I added K1’s forged steel crankshafts PN 346-4000RB6F-24 which is stress-relieved and has nitrided journals that prolong their life expectancy.
Once you have all these parts, it’s time to machine them to match, and yes, if you thought you could build a 408 Stroker from parts without cleaning and machining, guess again. Now you can buy all these parts online, or you can scrounge around and buy used parts. The difference in the budget is also reflected in the difference in life expectancy.
If you can afford it, buy a 408 Stroker crate engine, they are made to perfection and can be further tweaked at home. However, if you have the time and energy, build one yourself, but remember, the cost is more to build one yourself, and why? Because the cost is not just parts, it’s labor and tooling. When you add the cost of your time and the tools you use (depreciation) you end up spending more than a kit. Work it out if you don’t believe me.