Rear engine mount spring

[Italdesign]

This may seem a silly question but why is the engine mounting sooo soft on the Fiat 500/126?  I have fitted a Panda 30 head with a Dellorto DHLA 40 to my Niki. I am in the process of modifying my mount to better support the carburettor but I also wondered if a stiffer rear engine mount or some sort of stabilzing bar(for the motor) might help it run a little better.
 
Can anyone shed any light on this?   What would be the pros and cons of such modifications, and if this is advisable where might I be able to source the parts?

Regards
Stephen

[bis13]

i have used a cut down dirt bike spring in the past which was very much stiffer , and you can fit a stabilizing bar easily if you wish to stop the engine rocking i think you can buy the stabilisers in italy but its easier to rig up something yourself it wont be too hard.

[phreak97]

lol i just posted about this.. I cut up a rubber bump stop and added it inside the spring. look here:
http://club126uk.co.uk/smf/index.php?topic=3630.msg23148#msg23148

[Italdesign]

Thanks for the suggestions.

I've since found out that Middle Barton Garage have a heavy duty spring for modified engines (cost 12.50 pounds).

[phreak97]

it'd be interesting to see which is nicer over bumps.. mine feels much the same as normal until you hit a bump, harder springs would probably cause more general vibration..