What recommendations for sourcing a factory re-build of a 389 1966 GTO engine. Want to keep it original including high compression and original pistons,etc. I will be running pure 100% gas with tetraethyl for 100+ octane performance. Original engine has 120,000 miles and ran Pontiac strong prior to being placed in mothballs. Engine will require being crated & shipped, but want absolute best engine builder available. Goal is to have engine completed and returned as a "turn key" project.