Hi Marcosand welcome to the forum.
For starters how old are the two cars you have an eye on?
The +8 started life in '68. Narrow body with a Moss gearbox. In the early 70s (around '72) the Moss box was replaced by the Rover 4 speed and i believe the chassis was wideened by a couple of inches. By the mid 70s the 5 speed Rover replaced the 4 speed. The engine throughout this time was the 3.5 litre carburetted Rover.
In the mid-80s Morgan treated all wood frames with Cuprisol as standard. I can't remember exactly when fi was introduced on the 3.5. Nor when the 3.5 grew to 3.9. Subsequently this became 4.0 (still same engine size but a change from the earlier hotwire fuel injection).
In '97 +8s had galvanised chassis, stainless bulkhead and longer doors, as standard. The 'long door' models came about to move the top of the bulkhead forward by 2" to comply with yet more safety rules. The doors are longer by 2" and this does make ingress/egress slighly easier. The V8 eventually grew to 4.6 litre, before being withdrawn around 2005 - would not meet future emissions regs (but you'll know that form Marcos history I suspect).
The engines can be tweaked - best to look at some of the specialists in that area - Google should help.
Where in the UK are you?
