Everybody sit down, take a deep breath, forget most of what you have heard----and listen to what we do!
We use PAC valve springs, 1.500" in diameter, good to .900" lift. Seat pressure is 400, 1280 open. If you notice, we only go to .830" on the intake at the valve, even less on the exhaust. We do use 1/2" pushrods. Spring life so far last year was 48 passes---the springs still check out fine!
We don't try to get into that 1.000" lift range. Why? The heads still flow well----but not that much better than at .750" Why use crazy valve lifts when it doesn't give you that much more? Also, we preheat the oil---and keep it at 200 degrees for every run. Also, we use spring oilers---absolute necessary for decent valve spring life(take a lesson from the roundy round guys). And, after evey race weekend, we release valve spring pressure.
The P7 is a fine engine, short stroke, big bore. It doesn't have the torque that larger engines do but that is a matter of mechanical advantage. Yes, we probably get our little 358" to go a little faster/quicker----but it can get expensive real quick. For what it does, we are very happy. You have no idea how happy we are when we trailer a 500" supercharged BB FED with our little engine. And we are happy when our "friendly" competitors just shake their heads when they look at it!
