5.3 Engine with 243 heads valves hitting block
5.3 Engine with 243 heads valves hitting block I was told by a machine shop that with 243 heads on a 5.3 the intake valve will hit the cylinder wall and that you need to clearance the cylinder wall. Anyone else heard of this.
Sounds like you need to find a new machine shop that is familiar with LS engines 
But no this is not true. A lot of the new 5.3 engines come with 799 heads which are identical to the 243s.
But no this is not true. A lot of the new 5.3 engines come with 799 heads which are identical to the 243s.
The gen 4 5.3 trucks came with 243/799 heads stock, as did wifeys LS4 5.3 GP GXP, and a buddy is running 243s on his 5.3 turbo setup with no issues. Sounds like they are full of **** lol.
