Hi 300-o-philes, Still working away on the rebuilt 413 for my '63 Pace Car. My question is, what should I do about the heat-controlled valve in the right exhaust manifold? It is free, but swings from open (larger valve surface is 90 degrees downwind to exhaust flow) to past closed (larger of the valve surfaces points mildly upwind towards the exhaust flow). It is missing the anti-rattle spring, and the counterweight stop that attaches with the clamp screw appears to have rusted in two - it's too short to reach the pin. As assembled when I got it, the counterweight was mounted such that it prevented the valve from fully opening. That can't be right, can it? So should I 1) Weld the thing open and forget about it? 2) Try to get new parts and repair it per the factory manual? Where would I find parts? 3) Take off the counterweight and spring and just let the valve blow itself open when the engine starts? All wisdom appreciated, as always. Doug Jones Boulder Creek, CA tolerably close by to Jett Ranch