Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
What about DB-603 - production-vise it fits in 1942 at least as good as Griffon (maybe better?), and it's better in high altitudes. In second half of 1942 the BMW can fully operate at 'Notleistung', so that is a contender too.
My favorite is the R-2800 so far
With the rapid development of engines (and aircraft) during WW II even 11-12 months can show considerable differences. 1942 seems to be a rather pivotal year. For example in Jan you have the R-2800 in the A series with a single stage supercharger available in some numbers with the B series engines just starting production but the 2 stage engines, both mechanical and turbo are only around in prototype form. By the end of the year the both two stage engines are in full production and the A series has been out of production for months.
The Griffon only shows up in production form in the last couple of months and then in small numbers (a hundred or so?)
While the Sabre is certainly in production in numbers the question is when did it achieve a really acceptable level of reliability.
the best blend of power and reliability
reliability
Deliveries began in January 1943, two years later than the original plan had called for, and continued until September 1944
Do we have the numbers produced for Griffon and Db-603, yearly at least? The engine was produced (not only) for Me-410, and here is what Wikipedia says about the 410:
No difference when compared with Spit XII.