Searching for some gt40ps I came across tri-state cylinder head. These heads have larger valves 1.94/1.54. Is this a good improvement for these heads. I thought that having the smaller valves is what allowed them to flow better. Can anybody help me answer this question
I picked up a set of used GTP's an if I had seen those I might have gotten the tri-state ones instead...Here is a link of a guy that ported and polished his own gtp's an had larger valves installed...He then had them flow tested and was told the larger valves had no or little effect; http://www.diyporting.com/gt40p_home_porting.htm
he shows his flow results an on the last page..hope this helps
gt40p heads biger valves will help alot on power.BUT u will have to fly cut the piston to clear the biger valve if u dont fly cut the piston the valve can hit the pistons. that wont be a good thing bent a valve or brake the pision or brake off the valve. i have seen a valve brake off and blow of the side of the block. when a valve brake or bens no time to stop whats going to happen. stock 87-91 pistons have valve cut not every wide. stock ho valves are 1.78 intake and the 1.45 exaust gt40p have 1.84 intake and 1.45 exhaust valve.
I have bought a set or 2 of those from them. Great heads. They keep the bare castings in stock. They only build them when you order them so you could probably get whatever size valves you want. Just give Jim a call and see.