47 dodge 1/2T needs engine rebuild, suppliers? suggestions

[fourty1]

i just had an offer on a complete, pristine 1947 dodge 1/2T
from the grandson of the purchaser. The trucks' been sitting in a barn for 10 yrs.
it's so complete, it's amazing.
The radiator was drained several years ago.
Question ***any one recommend a source for a replacement flat head in the event the current engine is froze?
....the truck's too original to mess with ! I offered a good friend 1//2 interest to keep costs down.
update: just had my 41 chevy suspension completely rewelded & aligned. I get her back on the road tues.
thanks for the help
jim