Why will my 1957 TR 3 NOT rev past 3500 RPM without cutting out?
I have done a complete tune-up with new points, condenser, plugs, wires. I rebuilt fuel
pump and cleaned and adjusted the SU carbs. Timing has been set. Vehicle starts and
runs fine up to 3500 RPM, then it starts to misfire on all cylinders.
Try disconnecting and plugging the vacuum advance on the distributor and then try it, if it revs past 3500 without a problem then your trouble is more than likely a bad breaker plate in the distributor or the ground strap is broken.
I'm not at all familiar with TR3s and the ignition system. My guess would be to look at the fuel filter. I don't know what shape your gas tank is in but if your fuel filter is plugging up with rust that could be the cause. The solution to that is to have the tank cleaned and coated. Do not put a liner in the tank!