[Redcanuck]

Well I still can't find anymore data on the merlin 61 engine or anything useful for the merlin 63 engined spit IX; however I did run across a report that says that the F MK VIII and the F MK IX spits with the merlin 63 engine had basically identical performance.
http://www.spitfireperformance.com/spit8tac.html

So if you run across any F MK VIII performance tests with the merlin 63 engine it would be useful data.

So I dug into the info on the MK VIII in spitfireperfomance.com and discovered this:
http://www.spitfireperformance.com/jf934level.jpg
http://www.spitfireperformance.com/jf934climb.jpg
http://www.spitfireperformance.com/jf934time.jpg

Now the main text of this test refers to the tested ac being JF 934 with a merlin 66 engine but it is also called a F MK VIII not a LF. :?
That serial number for a MK VIII is probably a later LF but still one can hope

An opinions?

~S~ Redcanuck