Belmont111, these tanks are made to be exact replicas of the OEM ones, even the sensor locations are all the same. The only difference is that they're made of Aluminum instead of regular steel.
Make no mistake, these tanks are without a doubt a great upgrade even if you have good set of stock ones. Because given the age of the oem ones it's very likely they are starting to rust from the inside out and because they are powder coated they don't really show it. So they will even look okay from the outside and they're not. The worst is that you will have all of these rust pieces-flakes running through your cooling system and accumulating in your radiator...
When I took my engine apart I found a "bunch" of metal debris (close to a half a pound), inside my coolant jackets inside the Block. This is what made me realize that prob most Esprit users are not aware of this problem until these headers are literally falling apart in their finger tips when they check the coolant level and they are tighten their tank Caps.
I said it before and I say it again, I paid more for these tanks, and I waited few weeks for them (overseas shipping). Make these yours for less money and you don't even have to sit down and wait for them like i did!
JG