In an earlier thread, I eluded to a problem I'm having mounting my 552 directly on the flat top rail of my J&T 16" Car upper. The front housing of the site will not clear the standard carbine handguard when mounted forward to extend beyond the delta ring. I'm looking for an alternative mounting method, without having to spend the $300+ for a RAS type setup. Any advice would be appreciated.

An EO Tech mounted on a Swan Sleeve will be too high to co-witness. I used to have a Swan Sleeve on my AR so I've been there, done that.

I'm afraid I don't know of any other way to mount an EO Tech (and allow co-witnessing) other than on the receiver rail or the top rail of an FF RAS.

You can mount the EOTECH on the swan but it will not co witness you irons.  BUT that does not mean you cannot sight it in and use it on that rail.  It will work just fine and if you need the irons just give thw eotech a quick turn on the nob and get rid of it.  This is the only way you will save not getting a FF RAS.  It is not ideal but will work just fine.  I had my Eotech set up on my SIR this way for along time and it never gave me trouble not to mention I never needed to use the irons for lack of battery power!