Hi Richy,
I am more or less back to the land of the living, after 2 years of hell. Managed to get into the garage this weekend.
I can't make the 26th clashes with another meeting, but hope to be more active this year.
No issues mating together. But be aware the ST170 uses different engine mounts and because the water pump rotates a different direction you will need an extra idler pulley from Retro ford.
Kit spares sell one, a bit pricey but should give you an idea for making your own.
https://kitspares.co.uk/products/standard-floor-exhaust-mount
Sits right behind the back box.