What the heck happened in 3 years to the HP for the 350? When I was a teen my Dad had a 70 Chev Impala, totally stock. Clear as a bell I remember the sticker on the air cleaner, claiming 240HP. Did they ruin the stock 350 by 90HP in just 3 years?

I know it had the Rochester Quadrajet 4BBL, but can remember little else as to why it produced a stock 240HP. I do remember that it would roll out pretty damn good for a land yacht.. Glad my Dad never found out how hard I drove that big baby, or he would have me walking to this day..... I doubt if he ever redlined it through all three gears in all the time he owned it. It would shift into 2nd at about 64mph, into third at about 98mph, and pin the 120mph speedo easily in 3rd. Never did find out what its top speed was...not many radar guns in those day..thankfully!