So I picked up this little astro van with a cds 4.2 in it and am slowly bringing it up to spec. It wasn't producing a lot of heat initially so I back flushed the cooling system and heat exchangers. I have a pair of extra heat exchangers from an old cds and am wondering if it would be beneficial to add one or both to the existing system. I know it won't give me higher heat but am thinking it will sustain more heat through a large flow tool like a zipper. Any thoughts?