So, as you may have noticed from my other thread, I picked up a 1960 600D with everything intact - the motor needs rebuilding, she's been sitting for 25 years.
My main question is for quick, easy upgrades - 27hp just won't cut it
What would you guys recommend that would be somewhat easy to find in the Continental US? I'm just down the road from Mr. Fiat (http://www.mrfiat.com).
Sorry I can't be more informative - let me know what info you need and I'll provide it.

Carbs? Pistons? Gaskets? Supercharger?

anyone?

looks like I'll just toss in a fuel cell in place of the gas tank, put some bigger/better flowing carbs in, and start hunting for other parts. Good start?

Pretty easy upgrade is a 903cc from an early Fiat 127, early 80's Panda or Uno (not sure if you have any of these models in the states?). That will give you in the region of 45hp and is a straightforward bolt in swap. Add the twin barrel Weber, inlet manifold, cylinder head and exhaust header from an 850 Coupe/Spider/Racer and you'll have around 52hp - almost a 100% power increase over standard. I've heard that 600D gearboxes will take well over 100hp but who knows
Don't be tempted by fitting 850 engine as it runs anticlockwise compared with the normal clockwise rotation of the 600 engine.So either you'll have 4 reverse gears and 1 forward or you'd need an 850 gearbox but this is more grief in fitting than its worth, just steal the bits mentioned above from the 850!

The 899 Cinquecento and Seicento engine is based on the 903 block sleeved down to 899.

This engine was supplied with fuel injection, don't know what the emissions laws are your side of the pond, but might be helpful.

Cheers

SPD