*Introduced late 1978. Black epoxy pre-amp but circuit different to Sting Ray. Toggle switches on control plat. Body contoured (Sting Ray is slab body). Maple neck with option of a slimmer nut width (Jazz Bass). PUPs similar to the Ray but smaller physical dimension. 3 bolt neck. Serials are "C00xxxx" (Sting Ray are "B00xxxx). Horse shoe style bridge. Top load for strings (no through-body).
*1979 black epoxy deleted from pre-amp but pre-amp remains same.
*Late 1979 Rosewood is an option (but not narrow nut). Some Rosewood are 3 bolt but in the main they're 4 bolt necks.
*1983 toggle switch changes to slide switch (different pickup selection). Neck PUP similar to Jazz Bass. Bridge PUP remains same. PUPs are soapbar (pole pieces not visible). Old pre-amp deleted and Sting Ray pre-amp used.
*1985 Ernie Ball adopts Sabre. Some early ones have the horse shoe bridge and "Cooxxxx" serial (rare). String retainer now on A and D strings (previously D and G). Initially the headstock logo is Pre-EB (rare) before "Ernie Ball" is added. Four dot markers past the 12th fret (Pre-EB had three). In the main, a Sting Ray style bridge is used and therefore a Pre-EB "B00xxxx" serial is used. But EB introduce an unprefixed five digit serial. So you could get both serials up to circa 1988. There after, only the five digit serials.
*1987 three band introduced as an option (rectangular board and same as SR5)
*Circa 1989 six bolt neck introduced (4 and 6 bolt run concurrent).
*1990 moon shaped pre-amp board introduced (same as SR5 first version).
Yes. Although the Sabre PUP body is physically smaller than the Sting Ray, the resistance of each of the two coils in each Sabre PUP is approx 3.8 K Ohm. As both are wired in parallel the resistance for each PUP (as a whole) is approx 1.9 K Ohm. That is approx the same as the PUP on the 1978 Ray. Prior to that the Sting Ray PUPs had longer pole pieces and lower resistance measurements. The diameter of the pole pieces for the Sabre and 'Ray are the same ie 3/8 inches.