What's the Difference Between a 350 and a 350 Vortec?

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Similarly, you may ask, will Vortec heads fit a 350?

Yes the 1996-02 L31 350 vortec heads will bolt to ANY gen 1 350 engine.

Secondly, how do I know if I have a 5.7 Vortec engine? One easy way to identify the 5.7L Vortec engine is to examine the cylinder heads. The GM Industrial Vortec cylinder head was made by installing LT1 Corvette ports into an iron casting. The intake manifold bolts on with an 8-bolt pattern, unlike most other 5.7 GM heads that bolt on with a 12-bolt pattern.

In respect to this, how much horsepower does a 350 Vortec have?

Horsepower = torque x RPM / 5250. The factory engines come with 2 or 4 bolt main caps (on the SBC this is the three in the middle - the two outboard remain 2 bolt). GM rates these blocks up to around ~350 horsepower.

How much HP does Vortec heads add?

Retaining the same carb, distributor and long tube headers, the power output jumped all the way up to 353 HP and 391 Lb-Ft of torque for a gain of 90 HP and 40 Lb-Ft of torque. Proving exactly what the right camshaft and cylinder heads has to offer a GM crate engine.