Tower does not have anything, and you may play hell trying to find parts for this discontinued engine.  In fact, I am not even sure they made a CL version.  But possibly.

Your best bet would be to measure the throat and get a venturi made by one of the vendors that does that.  They may actually know the size. Then, just use a Super Tigre style needle.  RSM sells these.   

OS offered a control line FP 60 version so I assumed like a FP 40 they would offer the parts. I bought the OS FP 40 conversion parts from Tower recently when converting a 40.

Steve

Steve - when I make venturis, I place the needle valve spigot right at the vena contracta and use equal tapers above and below that point, the lower taper is 3/4 the length of the upper taper.
I tap the venturi on one side only and screw the NVA in until the spigot end is at the center.

I've had very good results with this setup.

  Bob Z.

 I did a quick search, and OS did not show the CL parts in the parts list for this engine.  Tower did not have anything either.  They might be out there if you search, but I am gonna bet at the end of the day, you would be better off with an ST style needle assembly anyway, unless you are really wanting to create something stock.

Looks like the way to go.

Good call, Mike.

Bob Z.

I bought the combined NVA and venturi set (made in the Ukraine according to the seller?) Have also sent a message to Eric at RSM to see if he can match up a ST assembly with the FP 60.

Thanks for your help guys, have a good holiday.

Steve

This is my setup for the FP 60.
Even though I radiused the head, I still need to lower the compression a bit.
You can see where I've removed some metal to reduce weight a bit - still heavy at  just below 16 ounces. 
The venturi is not yet finished - still needs to be deburred and polished.
The modified K&B needle valve assembly fits perfectly.

I will soon try it in my heavy old Polaris, which originally flew with an ST 60.

   Bob Z.

Bob,

Thanks for the photos. I've got a Hardinge I can use and I can swap our the collets for a 6-jaw Buck Chuck. Figure I can use that to dial the head in, but I'd rather use a CNC to help keep it nice and hemispherical. When I go down that road I'm like, well, why not just make a new head?  How much are you dropping the compression? Strictly a hemi with no squish band?

Thanks,
Chuck

You really don't need that much precision for a hemi head. I've seen people do it by hand with a Dremel!
I turn it on my lathe using a .5 inch radius form tool.
Remember, you're dealing with high velocity compressible fluid flow/gas dynamics.
I should have but I did not measure the before and after compression ratio so I really do not know how much the ratio has been dropped. It felt very high to begin with.
Yes, the head has a small squish band - around .035.
Regarding the venturis, I create the tapers with a small boring bar and the compound feed normally set to 15 degrees.

Bob Z.