check the run out on the crankshaft..even if its new. Get the pin welded also.
Why weld the pin on the 250s. We rebuild hundreds of cranks each year. The 250s do not have a history of the cranks moving unless someone has stroked the crank. Unnecessary welding of the crank pin adds considerable cost to future rebuilds and those cranks that have the crank pin welded do not usually true up as well as non welded cranks.
The stroked cranks need to be welded because the crank pin holes are not heat treated after the new crank pin hole is machined in the crank web. The press fit on the crank pin holes is usually reduced to prevent the crank from cracking through the pin hole. The loose fit on the crank pin hole is another reason stroked cranks need to be welded.
We weld cranks when the press fit is too loose but do not recommend it on a crank that has a good press fit.