Where's the 340 crate engines???

Not disputing the rpm capabilities of the 340 but the 360 is no slouch in it's ability to turn rpm's either. Also, if your dirt track cars were using stock bottom ends the compression difference was on the order of two full points, approx. 10.5 on the 340 and less than 8.5 on the 360. And you mentioned 2.02 and 1.88 valves, 360's came with the 1.88 intake valves which will limit the top end power compared to a 340 with 2.02's.

I still contend that if you build two identical engines except for the small bore difference and the stroke difference the 360 will get you down the track, around the oval or through the road cross faster because it's going to make more power over a broader rpm range because of the additional displacement.