Just replaced the engine in my mk2 orion and other than a few teething issues it now starts and runs well...

Altho out on the road and driving it, its fine under load but when you let off the throttle the whole car feels like im driving over speed bumps (making a bump bump bump noise in the car also) There is nothing rubbing and the wheels are all balance/not buckled.

I had to swing the gearbox around abit in the bay to get the engine into place, im wondering if maybe ive damaged something inside the box?

Any advice/suggestions welcome - Cheers!