Could you tell me if this is an ss with this trim code 1-870, or style code31867bcd

That trim code indicates a bench seat on that year, the SS had bucket seats. Here is more info:>------For 1962-1964 cars, the trim codes can distinguish an Impala from an Impala SS. The Supersports came with bucket seats and all vinyl interiors which had their own unique trim codes. (see the interior trim code charts on this site) The same applies for 1965 cars however cloth/vinyl buckets were available in the regular Impala so check the codes but don't assume just because it has buckets, that it is an SS. Supersports for '65 had all vinyl buckets.

More Info on the SS models:>---------1963-RPO Z03 was the supersport option for '63. All supersports in this year had heavy duty springs. Standard engines for 63 were: A new 230cu in 6 cylinder rated at 140 hp or a 195hp 283. Optional engines included; 250hp 327 (L-30), 300hp 327 (L-74), 340hp 409 (L-33), 400hp 409 (L-31) and topping out with the 425hp 409 (L-80). Supersports of '63 had many cosmetic touches including; SS wheel covers, engine turned swirl pattern exterior trim, and SS badging. On the inside, the same swirl pattern was used around the dash controls and at each side of the speedometer. Supersport interiors consisted of front vinyl covered bucket seats accented with bright moldings, center divider console/floor shifter, and an all vinyl interior. Because of this, interior trim codes can help confirm an SS car as the Supersports had their own unique codes. (see the interior trim code charts on this site) SS convertibles came with standard 7.50x14 tires while sport coupes came with 7.00x14 tires. Station wagon and 409 cars had 8.00x14 Highway Rayon tires. SS cars came with a 14X5 inch wheel but optional heavy duty wheels 14x6JK rims were available.