If one is from GTR2 and the other from GTR1, yes, I believe textures from the older one to the newer one will work.
You'll have to extract the texture files from the "xxxxxMAP.gtr" (or is it xxxxxxMAP.gtl?) file.
You can use GEDITOR
to unpack/extract the textures from the older track and then repack it on the new one (or just place the extracted texture files in the "track-name" folder").
...can't confirm if it works but it's worth a try?