340 or 360?

Okay guy, I will give you an apples to apples comparison. Back in the 80's I had a 69 GTS Dart, I had a 0.030 over 340 in it with W2 heads, 10.6 compression, Crane cam(242/252 .532/.552 108 install at 106), 1 7/8 headers, 727 trans, 5000 converter,and 4.86 gears. My best time was 11.60, soon after it spun 5/6 rod bearings( funny the old saying engines always run there best just before they blow, that true for engines that don't run that well too). Put a 360 short block together with 0.060 over TRW 327 chevy pistons to get 10.5 compression out of it, the rest of the combo was same as above. That 0.060 over 360 ran 11.0, but the real story was the 1/8 mile times the .030 over 340(4.07 bore) ran 7.60's and the .060 over 360(4.06 bore) ran 6.80's, the reason the 360 did not run 10's is because it ran out of steam at 118 mph or 6700 rpm at the 1000 foot mark. The 340 ran 114 mph, the only difference in the car was the short blocks. I ran in Pro at the time and the quickest I could run was 11.0 so I never changed the combo.
For got to mention that was a hydraulic flat tappet Crane cam.