I've had 340 and 360 short blocks in the same car, with the same heads, cam, intake, carb etc. and this was the difference. The 340 ran 10.44 and the 360 ran 10.46. The difference was the 340 was being twisted to 8,000 while the 360 was only twisted to 7200. The 360 left harder but didn't have the top end charge of the 340. I used a 4600 converter and 5.13 gears with the 340 and a 4200 converter and 4.86 gears with the 360. The 360 was certainly not as hard on the valvetrain as the 340 but being a bracket car running at the bottom of its class I really liked the top end charge of the 340. But the bottom line is if you are going to stroke it anyway it's not going to matter.