Thread: Heads?

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The questions I would have on those test results is under the AFR's it shows 1.6:1 is that the rocker ratio? Are the Vortec heads using the same or 1.5:1 rockers?

Good Question - if you read the article at the link posted above it goes into all the detail.

The short answer is, no - the Vortec heads were using 1.5:1 rockers. The AFR's were first tested at 1.5:1 and then with 1.6:1. The 1.6 ratio increased lift from 0.480 inch to 0.512 inch and the duration by approximately 2-3 degrees. As expected, the increased valve lift and duration afforded another 13 hp and 4 more lb-ft of torque. CHP did not test the Vortecs with the higher ratio but the point being the AFR's out performed - but at a substantial cost.

Just read the article, no doubt the AFR's are better heads. It would be nice for them post results for both heads with both rocker ratios that way you'd have an apples to apples compairson.