[PeterAllen]

Rick - Thanks for that. I was trying to eliminate those calculations/estimates and get feedback on someone else's experience, i.e. someone who has experienced tyres rubbing on the tubs or arches.

However, I now think I have come at this from the wrong direction - a trait not unknown to me!

With the exhaust tucked up close to the floor and the tyre-well removed and replaced with a fuel cell there was a huge amount of clearance underneath, in fact I was able to lower the rear 90mm and sill have 110mm ground clearance. However with 16" rims and high aspect ratio tyres (225/70/16) I was left with only 55mm tyre/tub clearance as well as requiring repositioning of the struts of the IRS to eliminate the negative camber.

Last night I raised the rear 50mm (i.e. still down 40mm from standard) which created over 100mm tyre/tub clearance and leaves minimal negative camber. The car clearly looks higher at the rear but cars of the 60s did have good ground clearance so it actually enhances the character of the car - win, win.