Sean, this is your lucky day. I happen to have magazines from 1962 on up and here's what I found: Chevrolet introduced the bored out 348 c.i. as a 409 c.i. / 360hp / 409 lb/ft / 11.25c.r. ( RPO#580 ) option on the 1961 Impala SS models of which 142 were built. In 1962 they increased the hp to 380 and 420 lb / ft torque / 11.00 c.r. ( RPO #580 again ) to begin the model year and later boosted it to 409 / 409 / 420 @11.00 c..r which Car Life magazine tested in the Sept. 1962 issue driven by owner / racer Frank Sanders of Phoenix, Az. He ran 12.22 e.t @ 115 mph at Pomona in June 1962. Of course it was set up to his specs for racing only with a 4-spd xmsn, 4.56 rearend, modified springs, shocks, tires, etc. Writer of the test claims Frank was the fastest shifter he'd ever seen and was a full half-second faster than any of their test drivers. Nov. 1962 Hot Rod lists Dave Strickler from York, Pa winning the 1962 Nat'ls at Indy in the SS/S class in a 62' 409 ( Old Reliable ) with 12.97 e.t. and 113.35 mph. Sadly, Dave switched to Dodge in 1964 and was eliminated in the 1st round by Bobby Harrop, even though his e.t was quicker at 11.33 to Harrop's 11.66. Hot Rod magazine itself ran a 1962 Plymouth in SS / SA losing to Ramchargers Dodge in class eliminations and to Bill "Maverick" Golden in his 62 Dodge in Stock Eliminator with the fastest e.t. recorded for stock cars at 12.37 in an earlier run. Back the the bow-ties, in 1963 there were four hp offerings for the 409: 340, 400, 425, and 430. According to http://chevysupersports.com/Impala61-64.htm the 1961 409 / 360 tested by Motor Trend ran the 1/4 at 14.02 @ 98.14 mph w / 4.56 gears, or about a two seconds faster than the 300H which as we all know gave up a few ( hundred ) pounds in the weight dept. In other words, it got its butt kicked... seem to remember a national tour ( exhibition ) involving said 409 bubbletop and a super stock Dodge and I think the Dodge won most of the races. A more balanced pairing there. Hope that answers some of your questions. Del Kerney