On the other hand, a typical street engine will spend 70 percent or more of its time in between peak-torque and peak-horsepower engine speeds. Few street cars hit peak horsepower rpm in the quarter-mile in high gear. While peak horsepower is interesting, it can be deceiving, as our test engine in a typical street car with a 3.55 rear gear and a three-speed automatic only experiences 6,000 rpm (or more) twice in a typical quarter-mile pass, hitting this rpm at the top of First and Second gear. This led us to one more evaluation that should shed far more light on the question of which head is the best. On the plus side, the Vortec intake port flows 42 cfm better than the stock heads at 0.500-inch lift and 18 cfm better on the exhaust side. If you are considering Vortec heads, keep in mind that swapping them in will require these parts at additional cost.
In addition, you must use guided rocker arms and center-bolt valve covers, and the intake manifold bolt pattern is unique, requiring a specific intake manifold. This added roughly another $160 to the price of the heads but allowed us to use 1.6:1 roller rockers to level the playing field against the other heads in the test.
We anticipated this issue and used a set of Scoggin-Dickeymodified Vortec heads with the valve guides machined for additional clearance and fitted with better, Z28-style valvesprings. In stock form, the retainers hit the seals with valve lifts above this 0.450-inch figure. The main limitation with these heads in pure stock form is their inability to utilize valve lift above 0.450 inch. These heads were only used on a few models of Vortec truck engines, but their longevity is ensured because they flow so well. If anyone could link me some ready to rock heads that would fit my application I’d really appreciate it!The production-based iron Vortec head represents one of the best budget investments for power for the small-block Chevy. I plan on installing a high rise duel plane air intake, with a 1 inch spacer and a edelbrock 650 carb, I would also like a big lopey thumpy cam and lifter kit that will make a lot of tire shredding torque and sound really mean, I’ve heard vortec heads perform best at around 500 lift, so my cam will be around that size, but until I get the dough to install the big cam and carb I’ll stick with my mild cam and put my tbi on the intake with an adapter until I get the money for all that, which should work just fine.
I’m running short tube headers with true duel exaust (straight piped of course), with a mild cam and open air element.
Does anyone have any recommendations for ready to bolt on vortec heads already machined for around 500 or so lift? I’m looking for something cheap that includes most the hardware. Hey everyone, the summit 151124 vortec heads I originally wanted have been out of stock for some time now, says they’ll be back in stock in august and I don’t plan on waiting that long to do my head and intake swap.
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