Corvette Magazine

The LT1 Corvette engine demonstrates this point perfectly. Rated at 300 horsepower, the Second Generation edition of Chevrolet's ageless small block employed a highly efficient intake manifold, cylinder heads, camshaft and exhaust manifolds to become the highest horsepower traditional small block ever installed in a Corvette. In 1996, the LT4, essentially an LT1 with revamped cylinder heads and camshaft was rated at 330hp.
In modified form, LT1 (and LT4) engines display even more

Pete Incaudo, shown here flow testing a CNC ported LT1 head has designed port contours that add 28 horsepower to a stock engine. With other modifications, power increases are even greater.

impressive power figures, and as is the case with older, less sophisticated engines, improving air-processing capability is an essential operation if power output is to be raised. In the case of the LT1, although the cylinder heads have excellent air flow capacity (for stock castings) they are a major roadblock to significant power increases. Conventional porting techniques can certainly be an effective means of increasing airflow capacity, but CNC (computerized numerical control) porting is much more accurate and repeatable.
This was the background Mike Osucha of MORE Performance considered when he set about