350 hp out of a fairly stock 340

Overall it don't matter how much hp the 340 made just how well they worked, if it really only made 275 hp that's good obviously don't take much getting these cars going. I feel it probably made low 300 hp though.
I tend to agree, BUT you really touched on it that it doesn't take much for these little cars to GO, especially the early As. I'm continually impressed with Vixen's slant 6. I know it's not a V8 and never will be, but its torque curve is way different. That makes it very impressive. Even Kitty says all the time "this thing shouldn't be this fast", and she's right. It's just a good combination all the way around. It's a barrel of monkeys to drive.