Is a 5.7 vortec a ls motor

Like the blocks, the cylinder heads used on the various LS engines continued to evolve over the course of the program. Technically you can bolt any LS head to any LS engine, but due to varying bore and valve sizes you could run into valve-to-block clearance issues. So, a good rule of thumb is that LS1 and LS6 engines can only run LS1, LS6, and LS2 cathedral port heads (and their truck equivalents). LS2 engines, due to the larger 4.00-inch bore design, can run LS1, LS6, and LS2 cathedral port heads in addition to the newer rectangular port LS3/L92 heads. The LS3 engines (or any of the 6.2-liter-based variants like the L92, LSA, etc.) can run any head except the LS7 rectangular-port heads. LS7 engines can run any LS-series head, but running the smaller heads would be nonsensical from a performance standpoint. So, for best results make sure to match the cylinder to the bore size you're working with.

Nearly all LS engines utilize the same cylinder head bolt pattern, which is why the heads are so easily swapped around. Most have four 11mm bolts per cylinder (for a total of 10) along with an upper row of five 8mm bolts. The LS1 engines (including the LS6) had bolts of different lengths (in regards to the 11mm fasteners), but from 2004 forward all went to the same length. To better withstand boost, LS9 engines received 12mm bolts. Also, keep in mind that each head variant requires a compatible intake manifold, so an LS3 intake won't fit an LS7, and so forth. Of course there's a nearly endless array of aftermarket heads to choose from, some of which are hybrids (cathedral ports but with large LS3 sized intake valves, LS3 port but with LS7 rockers, etc. ). Below are the four main factory cylinder heads you'll encounter.

Debuting on the LS1 the cathedral port heads were named for the distinctive shape of their intake port. Any intake manifold (LS1, LS6, LS2) will work with these heads as well as Vortec intakes from cathedral port-headed variants. 241 castings (the casting number is found near the corner of the head) are the most common since they were used on every 4.8L and 5.3L truck engine as well as the early LS1s. The LS1 heads have 67cc chambers with 2.00/1.55-inch valves.

Other heads you'll run into are 852 or 706 castings which have smaller 61cc chambers and 1.89/1.55-inch valves. These are best for high-compression builds and really need larger valves and porting work. 799 heads (65cc chamber and 210cc intake runner) are pretty much 241 LS6 heads worked over for truck engines and thus are a real treasure to find when hunting through boneyards. Aside from the casting number, they have distinctive D-shaped exhaust ports. 243 castings are harder to come across and are sometimes called LS2 heads. On the truck side, these would be 035 or 317 castings (LQ9/LQ4) and featured 71cc chambers. You may even find 873 castings from the early LQ4 engines, but they are iron and not worth bothering with. Also, the early perimeter-bolt heads (933 and 806) are far less desirable. Remember, not all 243 heads are LS6 heads, but all LS6 heads are 243 castings. True LS6 heads will have the stainless steel hollow-stem valves.

Common Cathedral Port Production Casting #'s:

• 933—1997 models, aluminum, perimeter-bolt valve covers, 5.7 liters
• 806—'97-'98, aluminum, perimeter-bolt, 5.7
• 853—'99-'00 (LS1), aluminum, center-bolt, 5.7 (66.67cc)
• 241—'01-'03 (updated LS1), aluminum, center-bolt, 5.7 (66.67cc)
• 243 —'04-up (LS6/LS2), aluminum, center bolt, 5.7; also in some '05-up trucks (64.45cc)
• 706/852/862—'99-up 4.8-5.3 truck heads (61.15cc)
• 035/317/873—'99-up LQ9 and LQ4 6.0 truck heads (71.06cc)
• 799—'05-up 4.8-5.3 truck heads; these are basically 243 Heads

The LS2 (6.0 liter, 364ci) was a large evolution of the platform and was given a Gen IV designation. The LS2 debuted in 2005 in the Corvette (400 hp), GTO (350 hp), and the concept-car-inspired SSR (390 hp). It also found its way into the Trailblazer SS (395 hp) and the Holden-based 2008 Pontiac G8 GT (361 hp). Early LS2 engines had 24x reluctor wheels and 1x cam sprockets while later ones transitioned to the 58x reluctor and 4x cam sprocket arrangement.

The increased displacement meant more power and the increased bore meant it worked with LS1/LS6 heads as well as the newer LS3/L92 versions. Depending on the year and platform, the LS2 could have come with either head. While there were vast differences between the Gen II V-8 and the Gen III V-8, the differences between Gen III and Gen IV engines are nearly unnoticeable at first glance. Provisions for active fuel management were added to most of the blocks and the bore size increased to 4.000 inches. Sensors also moved around and changed a bit. For example, the cam sensor moved from behind the intake to the front timing cover and the crank sensor changed from black (24x) to grey (58x). Due to the long cylinder sleeves LS2 blocks are great for stroking, and a 4.000-inch crank will make a 408.

Are Vortec and LS motors the same?

Is a Vortec 5.3 an LS engine?

Is Vortec LS or LT?

What engines are considered LS?