About the 340

perfacar said
hi, the rod/ stroke ratio is better in the 340. the ratio is 1.85. the 360 is 1.71.
when the crank is at 90 degrees to the bore, the 360 rod angle is more compared to the 340. more angle pushes harder on the cylinder wall, causes more friction. the 340 will take more RPM ever the 360. the bore to stroke ratio is better in the 340. larger bore with shorter stroke. both are good motors, depends on what you prefer. personally, I like the 340, it's a tough motor, makes very good power! In running a stocker, have found that a cam profile that works in a 360 doesn't work very well in a 340.

As stated the rod to stroke ratio is better generally and is better in the examples given but not in all situations. The rod to stroke ratio of the 360 is better than the 340 in a 1/4 mile oval track application. In a short track application the car will lap time faster with a motor that comes off the corner well as opposed to a motor that pulls stronger towards the end of the straightaway. A motor with a rod to stroke ratio of 1.65 to 1.75 is ideal in this situation of coming off the corner. A 350 chev has a rod to stroke ratio of 1.63, a 360 Mopar comes of the corner much better because the chev is under the ideal rod to stroke ratio.

Also perfacar is spot on with the cam thing, you wouldn't think that just because of a rod to stroke ratio change would make a difference but it does.

Chuck