Question can i replace my original side terminal battery. (cca 770) 100-6yr
with a (cca 880) 79-6yr as this is the only one i can get my hand'* on at the moment here in the UK



sorry for the size of the photo

Hmmmm...photo link'* not working...at least not for me.

Anyway, if the battery fits and has enough amperage, and it looks like it does, then you should be OK. Just make sure that it is held down and in properly without any undue stress on the case.

Bigger will not hurt the vehicle.....but make sure that it fits into the slot of the orignal battery......

i replaced mine with a different group battery, and hth vent tubes were not large enough to fit on the larger battery, i just used some fuel hose to lengthen the vent tubes and it wored fine.

is the battery under the seat like in park avenues

Yes, the battery is located under rear bench seat, right side. And it is vented to the outside atmosphere through a vent tube that penetrates the floorboard.