Tom-
The nice thing about RockAuto is they use the manufacturer numbers - so the ones Keith reported would work. But I usually just navigate to a Triumph model, either 50's TR3 or 60's TR4, then see what it has. Unrelated to bearings, but this was a great place to buy a Speedi-sleeve for the front timing cover. Typical price is about $30, I picked one up last year for $13 (they've gone up now though).
Randy