IM frequently nearly broke so I know exactly where your at!
when I usually start a project LIKE THAT I start by visiting the local salvage yards , and looking on craigs list and in the local bargain shopper, start asking around about suburbans and motor homes with bad transmissions, and for looking for a reasonably low mileage WRECK with the basic engine block I want, ask for deals at local machine shops, you can usually be fairly sure the car was running and the engine was functioning if the cars in the salvage yard due to being in an accident rather that being junked with NO MAJOR IMPACT TRAMA which might indicate the engine or trans failed (SOMETIMES A BAD CANDIDATE for a block ) but I see cars that had bad electronics or lots of rust that have decent engines occasionally.
ID look for an IMPALA or PICK-UP truck from the mid 1980s or newer as a source, but KNOW what your looking at, print out a MORTEC CASTING NUMBERS LIST,
you should be able to find a whole sbc core 350 to rebuild for between $250-$400
http://www.mortec.com/castnum.htm
you can look here!
http://www.speedwaymotors.com/Premium-S ... ,3177.html
https://secure.pawengineparts.com/shopp ... catid=1477
http://www.speedomotive.com/
http://www.adperformance.com/index.php? ... ath=71_231
yes its almost always best to by a complete rotating assembly
crank,rods,pistons,rings,bearings,damper,flex plate ETC
from a SINGLE SOURCE PACKAGE DEAL