boiler question: put in new block assembly or replace boiler?

Boiler is a 1996 Burnham Series II 203 standard vent 66,000 BTU gross with leaking block.
New block assembly cost is $330+$90 shipping+tax. New crown boiler is $1340+tax
I am doing the work myself.
Thanks for your opinion
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.