The motor is too big to fit into an EW350 frame. 
The gearbox for the 600 is a WG... and has a wider spacing underneath to mount on the frame. 
Yes the heads are detachable. 
Paul. 

Do we know if all the cams and gears are inside that (unbolted) timing cover ?

Will this bolt into an EW350  ?
Same gearbox ?

5 pics of the front, none of the back or sides or underneath !!
Do the 'heads' bolt on, they seem to be separate ?

Hi , can anyone help with replacement belt for my Duggie. Keeps breaking the leather straps evertyime I go for test ride, using an old spare belt but needs better quality one.

I need an 80+ crankcase, the front half anyway, the LH cylinder base bolts have pulled out and cracked the case. Judging by the welding already present, this has happened before. 

Or recommendation for a really good welder near Swindon!

Thanks

looking for spare parts list and manual for the 4-speed gearbox of my T6
Regards
     Manfred 

Thanks mate! Updated ad!

I am not a tunner so I cannot offer useful carburetor advice, but you might want to mention what carburetors you have fitted. Douglas used several types over the years. AMAC and track Amal to name but two. Or it could have any other make & model carburetor fitted in the intervening years. 

On the cinder track they originally ran a 50-50 mix of Pertol-Benzol mix. But the same engine as a road model ran happily on petrol, and in sprinting events they have run on petrol, methanol, and 10% nitro-methane (briefly!) It is a matter of having the right compression ratio, carburetor, timing, and ignition for the fuel you are using.

Douglas used the same cams (there were several) for cinder track racing as for the road models; though usually with a single carburetor on the road models.

With the anti-fouling pockets for the spark plugs, they tended to run a little more ignition advance than normal. My 1934 OW1 model (descendant of the DT) likes 40-35 degrees advance. If those pockets have been drilled out, the timing is going to be more in line with other marques on a given fuel. 

There is no source for the original style head sealing rings that I know of. Myself and others have made them using the method shown in this post:

https://www.douglasmotorcycles.net/index.php?msg=31133

-Doug

If of any help re your resto, attached is a copy of  the invoice for new chain that I purchased for my CW. Renolds were very helpful and I always buy a couple of half-links " just in case".

Thankyou they are perfect.

These two posts might help.

Rear:
https://www.douglasmotorcycles.net/index.php?msg=20589

Front: Pics assembled further down in post.
https://www.douglasmotorcycles.net/index.php?msg=23550

-Doug