LS3 vs Coyote

[scottj]

Originally Posted by Aussie Mike

There were plenty of other GM designs they had to draw from too. As an example Dart make a Buick head for the SB chev that uses the port design and shape from the V6. A style that looks very similar to the what the LS7 uses.

I believe these were the go to SBC head for a while in NASCAR in the 90's

The 1990's was the era of the "corporate engine" at GM. Pontiac developed the 867 head for NASCAR. Buick wanted a head for their NASCAR teams so they contracted DART to make a head based on the V6 head, but NASCAR disallowed it, so the Buick head landed in NHRA. The T&D rocker arm business was built on contracts from Buick for developing shaft rocker for that head. The 18 degree high port head was the dominate GM head in the 90's until 1998 when Chevy released their first NASCAR specific head the canted valve SB2. The aftermarket continues development of the 18 degree head to this day for dirt late models and off road truck racing. The evolution has taken it from 18 degrees to 16,15, 13, 11, and now 9 degrees.

As far as the LS heads, specifically the LS3 and the LS7, being copys of the Cleveland... I don't buy it. I see more similarity to the 18 degree and its derivatives. If anything, the SB2 with canted valves is closer to the Cleveland than the LS.