Hi All !

Is it easy to change a speedo. After market into same gap ect

thanks

It all depends on how you view easy 
Your old/current speedo may have all the connections bulbs etc for you lights indicators etc and the aftermarket non, in wich case you may have to conider adding exrta lights, switches etc on your dash,
the aftermarket speedo will be set at a standard calibration which may not match your wheel size and so give a false reading resulting in either horn beeps or tickets.
and maybe a new speedo cable with the correct fitting for the aftermarket one (extreemly doubtfull youll get a new cable with a new speedo)
fitting bracket and instructions should come with a new one

bodywork wise its easy, if new one is smaller you can make a plate to go over the old space and have it cut to slot the new one in,
if its bigger than the old space simples, mark out the area to be shaved/sanded back and just take your time doing it.

Rich 

thank you i am going to have to look into connection. I know the indicator shows when it is on, on there and there is also a oil light. Fuel gauge does not work . I use a stick aha

thanks

Forgot to say, i'm sure i read somewhere that for mot purposes the mileage has to be proved as a new aftermarket speedo will only read the test milage usually around 4-5 miles.
Not that just an old mot will do, the old mileage has to be either stamped on the chasis or a recognised (by the garage) sticker note with the old mileage on it visable near the new speedo, so as to add to the 2 mileages together in the mot,
I'm sure someone will post here or link the correct answer if i'm way off the mark with that one.
another option would be to have the new speedo clocked forward to match the old one
Rich