Yep kind of re-enforces what I've been saying about the heads. But the use of the larger valves hurts the velocity on the intake side, now on the exh. side the larger valve helps tq.. If he checked the flow with the smaller valve and the larger valve and did the calculations he would have found that the smaller valves would have moved more air sooner with the head in ported form. With the smaller valve moving more air the tq. and the hp will come up. The difference that I found is about 40 hp more with the heads modified the same on a 318 engine. Keep in mind that a 302 casting head is only 118-120 cc's from the factory and that is why the factory used a 1.78 intake valve and not a 1.88 valve. The 1.88 valve needs to be in a head with 140 cc's or more and without major welding and rework the 302 head will never get this large. And on the flow bench there's not a 5 cfm difference at peak. And with the larger valve the low lift flows are less than the 1.78 and when using a cam thats .500 lift or just over the low lift flows are very important. On one of our cars we had the 360 heads with the 1.88 intake valves and it ran a best of 7.48 in the 1/8, and then we switched the heads to the 302's with the smaller intake valve and the larger exh. valves, and the car ran 7.31 in the 1/8 so with actual track testing this is where I get my info from. If you noticed that he never attemped to try the smaller valves in his artical, he just went straight to the 1.88 valves.
