How easy is it to change from S Type to Tillett seats?

[Green George]

I am thinking of changing from the leather S type seats to Tilletts. I have bracing under the floor for the current floor mounting points in the shape of 'U' profile metal strips.

How easy/straightforward is this job to do? From the little, research I have done, I think I have established that the S3 runners should fit the Tillett seats, but will not line up with the current mounting holes in the floor?

My Torso is long, which means with a helmet on my head is inline / slightly above the roll bar, so I will need to tilt the seat back, which I think quite common.

I really do not want to botch the job so was looking for some guidance/pointers, please.

[rene7]

It;s a simple job - you may have to redrill the mounting holes, to suit the runners, I've done this twice, first time was a simple remove tillets and bolt in leathers, the fitted runners used the existing holes second time i had to drill new mount holes, but thinking about it now maybe I could have simply swopped the runners.
Hope this helps