Great advice - thank you all.
I'd only mentioned using a 6.5T as I happen to have one in the garage and the 14T fitted sounds a little slow. I haven't driven the car yet as I am awaiting a receiver so I can run it from my existing radio.
I am not a total newbie in that I ran Hotshots and Optimas back in the early to mid 80s, but I have certainly had quite a break. I took a 2nd hand b44.1 to my local track recently and I can still get it round reasonably quick, but lacking a certain finesse. I guess I'd be more "rustie" than "newbie"
I will run it first with existing Orion stuff before I start changing parts.
Now... onto those damaged rear hubs...