When I used to run dirt track cars you could tell a big difference between a 340 & a 360. the 360 had a lot more torgue and pulled hard out of the corner, but flattened out pretty quick. 360 also wouldn't live as long.
340 would come to life just exiting the corner but it would not stop until you backed off the gas.
Bye the way, all parts where stock except the purple shaft came we ran, Even the vavle springs where stock,if I remember right I think it was the valve springs the pink stipe or something like that. And the 340 would twist about 8 grand with out no probs.