I found a book online that I'd like to purchase about the Matra Le Mans cars, and one thing that I've always wondered about is the 670 and the different versions of them. And the previews I read from this book only muddied waters a bit.
First of all, in this book (Matra Sports Cars), it's said that the first 670s were basically R&D vehicles made to use up 660 left overs. However, I do wonder if that's far fetched, as the 660 and 670 looked markedly different, even around the cockpit area where the main chassis resides.
Another source of confusion is the "B" series 670s, which it seems that the main difference between them and the '72 670s was bodywork, namely a new nose with a concave section above the radiator intake that was missing from the '72 cars. Other than that, the cars seemed to be similar and the "B" designation was used to denote the new build cars. Also, one '72 670 was updated to "B" spec for LM that year it seems.
And then there's the "C" spec cars. I read online a very long time ago that the 670 C was supposed to be a major revision, but only a new nose with a "squared off" radiator intake (replacing the trademark Matra "upside down smile/frown intake), and newer short tail bodywork for the sprint races emerged for '74. Other than that, the C was basically the same as the B, and it also appeared that irregardless of bodywork, 2 of the 3 670's entered at LM were designated 670 Bs, even with the "C" bodywork.
Of course, I know about the 680, which had side mounted radiators and a much modified nose section. But even it wasn't an entirely new build car, being a re-bodied 670 B.
Can someone sort out fact from the murkiness about the history of the 670 lineage? How truly similar were the cars year to year, and if anyone has read the book, how accurate is it, as I'd like to buy it soon? Any Matra experts here at UCP?