That's a good deal and getting rid of the excessive height above the pin and the 250 pistons is an advantage. 620 bucks is a very fair price for low production high quality items.
I've heard endless discussions on rod length from tuners who spend a lot of time dyno and track testing engine changes .Almost all the discussions were V engine but the theory is the same for an inline.
They most all agreed a short rod increases low speed power and a long rod increases high speed power. The increases in power are often subtle and depend on the whole tuning package.
You can find more a lot of info on the Speed Talk forum.
