We just finished up with a set of prototye 5.7 cnc heads with 2.10" int/1.60" exh valves. The intake is flowing up to par as we figured, but the exhaust still needs a little help. We're going back to the bench with a larger exh valve to see if we can get the exh/int ratio where it should be. These new 5.7 heads should work very well with the 370/392, 5.7 based strokers and let you maintain the 5.7 intake manifold and your 5.7 headers, if you have them already. We'll keep you updated.
Right now the int/exh flow numbers are within a few cfm of of a cnc ported 6.1 that we tested these new 5.7 heads against. However the port velocity is 28 ft per/ sec faster. We'll be working on the exhaust side to get the exh:int ratio a tad better.
Here is a picture of our modified exhaust port. This port is only available for those with round tube headers. (including the flange) The flow picked up nicely. http://i280.photobucket.com/albums/kk179/Sharadon/Modifiedexhaustport006.jpg
