I have been doing a Study on the Original Tiger engines from a Ford parts and date code point of view. If you have any questions about your engine contact me; rfraser@bluefrog .com I will gladly answer your questions. If you have an original Tiger engine please participate in my Study. The more information I get the better we can all understand our Tigers.
As far as I can tell all 260 Tiger engines had the 7" mount and 3 freeze plugs. This was the same as the 289 engine. The best way to tell what engine you have is to look at the block casting number which down by the starter motor; there is also a casting date code nearby. Many of the 289 and 302 parts have 289 or 302 cast into the parts. The 260 parts has no such markings; you really need to go by the casting numbers on the parts to know what they are. The best book for understanding all these numbers is Bob Mannel’s Mustang & Ford Small Block V8 1962 – 1969. I use his book all the time.
All 260 blocks are painted black until the last batch in the B19KC engine group assembled in Oct 1965, they are painted blue. Maybe when people saw the blue engine they automatically thought it was a 289.
As for performance; 1st – Ford never upgraded the HP rating of the 260 engine after many of the parts were upgraded including the heads. The stock HP rating of 164 only applies to the very early 260 with small valves. I believe nearly all production Tigers have the upgraded heads and probably have an HP of 180 or so. You can do all the same upgrades to a 260 as you would to a 289 including a stroker kit, you just need to know what your doing and have money. I saw one listing for a 260 build including a stroker kit that got around 350 HP.