Sounds like you have an interesting car. The '61 Impala SS is greatly desired among Chevy collectors. Good luck finding parts if you are in the market, they are next to impossible to locate. Not all cars left the factory with a build sheet and Chevrolet is not going to reproduce one for you either. You could try looking on the top of the gas tank, under the carpet in the left rear passenger seat footwell, back panel of the passenger seat or drivers seat, radiator core support and the list goes on and on. Although, it might not be worth tearing the car apart looking for it. Here are some other things to look for to see if you have a true SS - the following options are mandatory. *One of the following motors - 305 hp, 340 hp or 350 hp 348 cubic inch or the 360 hp 409 motor. *Either a heavy duty Powerglide transmission or a 4 speed transmission if you chose the 305 HP motor (All other motors required a 4 speed transmission) *Heavy duty shock absorbers on the front & rear *Heavy duty springs, front & rear *Power steering *Tachometer *Dash pad *Power brakes *Metallic brakes * 8.00 x 14 1" wide whitewalls Other equipment consists of SS emblems on the deck lid and each quarter panel, solid center full wheel covers with 3 bar spinners. Interior equipment includes a grab bar on the passenger side and a trim plate or console with the 4 speed transmission. Chevrolet produced 453 Impala SS in 1961

Here is a picture of an original window sticker for a 61 impala ss [url]http://www.348-409.com/images/misc119.jpg[/url]