I put the 66 up Moroso 8 qt in my 65 with no problesm.I did make a small notch on the pass side just to have a little more clearance when I had the crappy rubber OE mounts,Now that I have the polys I wouldnt have done it or worried about it.I probally had3/9 clearance before I made a tiny adjustment.Now it like 1/2 or 5 /8.You would never notice it unless I showed you it.That was 12 years ago and no problems.Rocky