Triumph made a natural progression from the TR2 with the introduction of the TR3.
The front styling change to the egg box grill was a simple but obvious change, many
more important but
less obvious upgrades occurred during the TR3 life span. The engine first benefited
from the high port head, then the change to 1 3/4" SU carburettors resulting in a power
uplift to 100BHP. The axle was changed
to the stronger 6-bolt type (often referred to as the Girling type, due to the braking
system change that was introduced coincidentally). The drum brakes vanished in favour of
discs at the front, the whole system now being supplied by Girling.
Whilst all 'classic shape' TR's except the TR2 were all known by Triumph as 'TR3', We have come to know the wide mouth TR3 as the TR3A and the later left hand drive North American market TR3 as a TR3B. The TR3A was the best seller of the side screen cars. The larger 2138cc engine was optional from 1959. Production tailed off in 1961 resulting in production ceasing in that year.
Although the TR3A had stopped selling in 1961, North American dealers thought the TR4 was going to be too big and too expensive. As a result and at their demand, the TR3 was reintroduced and we know this car as the TR3B. The TR3B was produced in 1962 only in two forms, those with commission numbers prefixed TSF and those prefixed TCF.
TSF cars had TR3 3 synchro gearboxes whilst the TCf series has TR4 4 synchro gearboxes and 2138cc engines.
Commercially it was a flop as only 3334 cars were built of which only 530 were TSF.