P.,


The engine is most likely the #3068 Quickie.

Make sure the carburettor has a 9 mm choke size, which the Quickie is endowed with.
The bearings should be the phenolic retainer WIBs.

The exhaust duration on the Quickie's sleeve is about 180º; not the 155º of the normal .40 engine.


The tuned silencer in the photo seems to be the normal #3248. If the distance from the front face of the canister to the end of the 'stinger' is 175 mm, as it seems, it will not allow the engine to exceed ~15,500 RPM.
The #3246 is for up to 23K - you need that!

...The #3235 will not fit this engine - and it is a normal silencer.

The header is a Macs and it is significantly longer than the original MVVS unit (and some say it is of better quality).
It is designed to be trimmed to length. And if you want to use it with that 7.4x7.5 APC C/F prop, north of 20K, you'll have to do it.