Make sure you got a good radiator if you remove the heater. Some days in summer I have to run the heater or pull over.
IMO unless it's a strip car why bother. The 50lbs (maybe just throwin it out there) isn't gonna make a huge difference. But if you also throw your battery in the trunk it could be a noticable weight gain.
Where the heater hoses go into the firewall there is a cover there. I'd probly take the whole assembly out from under the dash and leave the one in the firewall unless you want to cover it with something else. I wouldn't weld something on though so you can put the heater back in.
Drain the antifreeze then remove it, and try really hard to not get antifreeze on your carpet. You'll need to have a shop drain the AC fluid etc.
Also do a search on heater cores, alot of posts on it.
[This message has been edited by 67stock (edited 03-09-2001).]