I've been trying to track down a stumbling /missing problem I'm having with my TR3 so I'm going to take the advice of this Forum and send out the Dist to have it recurved and Vac Advance checked. I've also discovered from Competion manual that the carbs should have to the RH needles (richer) if you are running a header like I am so I'm going to switch out the needles to RH. Odd thing is the plugs are looking sooty black which is an indication of Rich mixture!??? My question is: should I put the recalibrated Dist in first to see how it runs then switch out the needles if needed or change the needles and Dist and then test? Karl.... TR3 with rebuilt motor,rebuilt carbs,TR4A intake manifold,heat shield,wrapped exhaust header.