Value of a 340

340's have the performance reputation because they were from the performance era. The 360 replaced the 340 as a "smog motor" and was choked back due to the emission requirments. However, if you take the 360 heads and open up the intake valves from 1.88" to 2.02" and up the compression to 9.2 to 9.5 to one. They will run just as good or better than the 340 especially with the longer stroke. Basically, you are putting the performance parts back on and getting rid of the smog parts.