Add .1mm headshim to the mix. You should be fine. Elevation also will have a factor so you kind of need to also have a idea of this as well.

For the IDM we have run the 2013,3031 as well as the 2033. We have seen no real big difference with the 2013 to the 2033. We like to keep with the 2033 and the 3031. But the 2013 does work and works well. Do not know for the Flash.

Thanks...sounds like 2013 is your recommendation here...

No I do not use this pipe. We use the 2033 and also 3031. I just said that the pipe works and others like it.

Thanks...just to add on here in regards to the IDM .21 Evo 3, do you have any problem running with it? is Evo 3 the latest released? sorry, am not quite familiar with this type of eng...currently mine is running with nova 35plus21.

No there are no issues it is the current model for the IDM.21 engine and they are completely different engines the Nova and the Picco base engines.

The IDM is certainly a nice engine, but the 35plus21 is a bit faster...

? the Picco and IDM are completely different engines?....

No the Nova and the Picco engines not Picco and IDM. LOL

Maybe, but the IDM is better on fuel. It takes a lot to get time at 301 with a 35 plus 21.

Thanks again for the feedback guys.....but now am getting more confuse here ...ok, if you're me....what would you choose..IDM or Nova? (ie, regardless to their prices)

Picco engines generally have more torque and less top end than Novas, but they are also better on fuel consumption.

They had a pre-pre-pre WC race in Lostallo 2 weeks ago with most of the top guns attending and Alberto Picco was once more the only one who was able to get 5 minutes on a tank.
Just like at the Euros two years ago, this might just be one of the deciding factors at this track when the worlds are on in August.

With a bit of work, you can get the topend out of a Picco, but the the fuel consumption will go up a bit as well.

I would go for the Picco and play with the gearing to reach the same top speed, simply because of the price difference.

Nova Rossis are probably the best engines out there, but the pricing structure is getting a bit ridiculous.

When you says Picco, would it means both Picco and IDM or just Picco itself?

Yep, IDM are Picco based engines just like Mega.

Thanks for the well explanation given...any recommended pipe to be used on this IDM?

That is completely up to you and what kind of engine you are looking for. The benefits to each engine that you have a choice of. Sorry but nothing to say other then take your time and know what you want out of the engine.