[mrrec]

Depends on the battery.

Top terminal: R59 was smooth top.
Side terminal: R89 was the "elephant" grain. Intro 1971.
R79S was smooth top. Intro mid-late 69 through 1970.
R79W was "elephant" grain. Intro mid-late 69 through 1970.

There is much confusion over this. There have been published photos of the R79S (smooth top) and it was called an R79W.

In the case of the LS6 Chevelle, the R79W is the correct battery. Cumby has the right R79W for his LS6 because, well, it came with the car! I have an NOS R79S as do a few other people I know. The R79W is VERY difficult to find as NOS (or as a no good, used, 36 year old battery that came with a car new!).

Additionally, The R79S or W has not been reproduced. The R89 HAS been reproduced and is identical to the R79W with the exception of the molded in model number on the side of the battery.

Furthermore, the earliest R79 (mid 69 - 70)had a larger thread positive cable connection than negative.

Sorry for the non-simple answer...
Anything to add or correct, Rick Mr70?

Dave