Long rods for cast crank 225?

I may end up buying the van next door. My buddy sold it to the neighbor. 1980 I believe. Solid lifter, peanut head, cast crank(?) 8.25 double tag rear end. 3:55's with a sure grip. I did what I call an RV port job on it. Rebuilt a super 6 BBD and pulled the 1bbl off and did the electro crap intake. It has the 833OD!
Now keep this in mind. A lot of people don't know this. There are TWO distinctly different slant 6 cast crankshafts. There's a light one and a heavy one. Pretty easy to tell apart, because the counterweights are a good bit smaller on the light cranks.