What motor did the 241 heads come on?
5.7L LS1
The 241 heads were used on 5.7L LS1 applications and are considered by many to be just a minor step up in performance from the 706.
What’s the difference between 241 heads and 243 heads?
The 243 heads flow 10 cfm more on the intake side, and like 7 cfm more on the exhaust side (if memory serves me correctly). The combustion chamber is a difference of 3cc smaller on the 243’s. Valve sizes are identical in both sets of heads.
What size valves are in 241 heads?
In terms of cylinder heads, we included the 706 small-valve 5.3L heads, the 241 (LS1), 317 (6.0L truck), and 799 (as a stand-in for the hallowed 243) heads. The idea was to flow and measure each head, then follow up with the all-important dyno testing.
What vehicles did 243 heads come on?
The 243 head came on the more powerful LS6 engine from 2001 to 2006, and was used in C5 Corvettes. Later engines like the truck-spec LQ9 and LQ4 used the exact same port design as the LS6’s 243 heads, but had 6 cc larger combustion chambers.
What is the best stock LS head?
The LS6 was designed specifically by GM to surpass the LS1 as the best performance head, and it did such a good job that the “243” casting was recycled on the LS2. Aside from the LQ9, which is a copy of the LS6, these are the best performing of the OEM cathedral ports.
Will LS3 heads fit LS1?
The heads will physically fit on the block, but the valves will hit the deck because the LS1 bore is too small.
What heads do LS1?
The LS1 heads have 67cc chambers with 2.00/1.55-inch valves. Other heads you’ll run into are 852 and 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.
How much HP do ported heads add?
Porting the heads will definitely help airflow. You will gain 25 HP over the stock setup.
What LS engines have cathedral port heads?
Cathedral port heads came on the original (Gen III) LS1, but were also used on the performance-oriented LS2 and LS6 versions. Cathedral port heads were bolted on literally millions of truck variants, which included (among others) the 4.8L LR4, the 5.3L LM7, and 6.0L LQ4.
