Hi,
/ubbthreads/images/graemlins/iagree.gif I agree that a Bentley manual is most likely the best, primary source of info. It's a very complete reprint of the factory service manual. (I don't have Spitfire book yet, but do have several other Triumph Bentley manuals and they are all good.)
There are some good arguments in favor of getting one or more of the other manuals (Haynes, Chilton and Autobook are three I have for various models). For one thing, these are often useful with info of how to do repairs using common tools, rather than "special factory tools". The factory manual virtually always directs you to use this, that or the other special factory tool that the service department or an authorized repair facility might be expected to have on hand, but most of the rest of us certainly won't have available.
Some of the Bentley manuals can be a little confusing with all the info they contain. For example, the GT6 reprint tries to cover all three models of the car, and has sub-sections devoted to each within each major repair section, but only in cases where there are differences between the models. There are also reprints of the Mark I, GT6+ and Mark III owner's manuals (which have a lot more repair and service detail than the typical owner's manual). It's obvious reading some sections that there was a version that dealt with Mark I and Mark II differences, written before the Mark III was produced. So it refers "GT6" and "Other than GT6", which often should be interpreted as meaning Mark I and Mark II (aka GT6+). Then it's a matter of looking to see if there is further information regarding Mark III, or trying to sort out if "Other than GT6" means Mark III as well. In other places the info has obviously been re-written to reflect the differences between all three models. It can be a bit confusing! But, so long as you are aware of this, you can sort it out.
I would bet a comprehensive Spitfire manual would also be crowded with this sort of thing, since there were more variants of the car and the production timeline was so much longer than GT6! It might be worthwhile to try to get the specific, original manual for your car, if at all possible. I've had good luck picking up a few of these off auction sites and Amazon. On the other hand, it can be useful to know about changes to the cars, from one variant to the next.
The factory spare parts manual is an excellent supplement, too. Reprints of these do not necessarily follow the same pattern as the service manuals. For example, TR4 and TR4A service manuals are combined into one Bentley reprint. However, the spare parts manuals are two separate books.
The major vendor catalogs are also quite useful. Moss and Vicky Brit have lots of illustrations and "exploded views", but each have their own, unique parts numbering systems. Rimmer Bros. and Revington TR generally use original factory numbers. The Roadster Factory overall doesn't produce comprehensive catalogs, but does use the original parts numbers. (TRF does print smaller "glovebox" parts catalogs, but these are somewhat limited to the most common parts. They have a more fully detailed "Spitfire 1500" catalog, too, that I'm aware of.)
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