Be more specific.

What kind of eclipse and what kind of Spyder? The radiator and fans are interchangeable between 4g63 and 4g64. Not sure about 420a though, but it appears to be very similar. So a 4g63 radiator will drop into a 4g64 Spyder, and vice versa. However, the coolant inlet/outlet are in different locations depending on which radiator. So you may need to find the right shape hose, or just buy one that is flexible.

well i was thinking since the 99 eclipse have the radioator cap by the head but the spyder 2.4 sohc has on the radiator .can i do a conversion

The 4g64 in both the 2g and 3g have the rad cap on the t-stat housing (see pic). The only benefit to using a Spyder GS radiator is that it shifts the radiator hose to the left. That give you the ability to use larger/taller exhaust manifolds that would normally fry the radiator hose.

Well mine is like that

Well that is a galant 4g64. Most likely a galant radiator as well.You need to put the spyder coolant neck on it for a spyder radiator. Did some one rewire the car for the galant distributor?

No it's a galant . I just wanted to get a better radiator like my 2 g but found out the neck was different that's why I was trying to figure out if its possible

Yes its possible. The pins on the bottom of the eclipse may be in a different location and would need to be moved and welded if so.

So the radiator won't fit but I can put the coolant neck

Can I buy this Look at this on eBay:

95-99 2G 2 Gen DSM 4g63 Eclipse Talon Water pipe coolant tube thermostat housing

http://bit.ly/VpjJcI

I just remembered I tired to put a galant radiator in my 2g a few weeks ago the galant radiator is taller. So to put a 2g radiator in a galant it would take a custom lower bracket and the 2g fans and re-wire them for the galant pigtails.

No you need the spyder 4g64 parts.

Dam that's sucks I guess I going with a stock radiator