I'm pretty sure my coolant seals are going, here are my symptoms: Overheats sometimes only when coolant is low, but it's low constently. i have to fill it up everytime i drive. Last time i started it up, it blew that dreaded sweet white smoke, but it's only on start-ups. When cranking w/out ign fuse in, the coolant reservoir bubbles. So if you guys concur, the next question would be what is the min i need to get to change coolant seals. It was rebilt when it was streetported of course, but i don't know how long ago that was. Thanks for your help, Julio

another possibility would be a cracked housing..

Minimum is a rebuild to replace them. I'm have similar issues but not as severe as yours.

I've heard of people putting stuff in the radiator like alumaseal with positive results.

The one sure way to fix a coolant seal is to rebuild it.