LSx is a completely different design, sharing ZERO architecture with previous small blocks. It much more closely resembles the Ford "Windsor" small blocks (289, 302, 351W) as far as layout and valve spacing. The firing order is not similar to any of them. The only two part numbers found in LS1 that were used in small blocks are the rod bearing and the hydraulic roller lifter, both of which are used in other modern GM engines as well.
Jim
So what you are saying is that the firing order of the LSx is not similar to any of the Windsor Ford engines? We've already established that it's not the same as the SBC. Does that include the Ford 351W or the 5.0 HO, which have exactly the same firing order as the LSx?
Seems like the LSx is NOTHING like the SBC but is similar to the Ford Windsor. I wonder who else knows about this. What would cause such a monumental philosophical shift at a place like Chevrolet to cause them to make such a change to an ideal that's been around for over 50 years?
