Can a two core radiator be converted to a three or four core or do you start over with a new one?

The trick would be to find a shop that still builds radiators! I'd guess they could use your end-tanks and re-fit a 4 row core to them.

As John D said, going to tough to find someone to build you one. Ground Up has a nice four core (auto) for $350.00. http://www.ss396.com/mm5/merchant.mvc?Screen=PROD&Store_Code=chevellecamino&Product_Code=AKY-844A&Category_Code=RADIATORS

Just get a new Desert Cooler from Auto City Classics. That is unless you have an attachment to the old one.

That last 3 row I put a new core in ran about $300 and that was about 5 yrs ago at an old radiator shop in Red Wing. Would imagine the cost to be quite a bit more today. Why not go with a new 4 row or those extra wide 2 rows that are suppose to be 30% more efficient than a 4 row?

The guy that pulled my radiator didn't look real close and thought it was a two core since it was thin. We took a closer look and it is a three core. My 396 always ran cool. I took it in to have it checked, cleaned and tested. Once I paint it, it will go back in with the 454.