Sorry guys...i only know of 2 stock 340 builds.
One dynoed 276 and the other was 286 hp. The Dulchich stock rebuild was around 280 i believe?
The 71 engines with the 800 thermoquad will gain another 15 hp and could eclipse 300 hp above 5000 rpm.
...and i think the earliest 340's only had a 565 cfm carb, but that is something i read.