How much difference in size is there between 1/32 and 1/35?

1/35 is about 8% smaller than 1/32nd.

The only way will be to suck it & see, eg offer up the replacement duty pilot & M60, then check it with your MK1 eyeball.

IF it looks right to you, it is!  

The BIG (or Little) caveat is that even in 1/35th scale different mfrs will have different sized versions of the same item. !

With Figures, early Tamiya figs scale out to approx 5' & Airfix Multipose at about 6'+ with everything in-between, but not everybody in the same squad will be the same hight, eh?

Make sure common items, helmets, weapons, packs etc, are from the same mfr, to make sure they don't look wrong.

Good luck.

Excellent, thanks.  

8% doesn't sound like it'd be too noticeable.

I have the figures to size them up because I have them in my 1/35 Academy UH-1C kit, so checking those won't be an issue, just have to buy a 2nd set of them if they do look OK.

Using the miniguns on the UH-1C as a reference the barrels are roughly 15mm long, so 15mm+8% = 16.2mm, so barely any perceivable difference.  Assuming the Werners Wings barrels are of a similar length I'll hazard a guess to say his exposed XM27 system will look perfectly acceptable on a 1/32 kit.

Mixing 1/32 and 1/35 is not an issue.  I have done it often.  The key is to keep all like items, weapons, gear, etc, in the same scale.  The size difference between 1/32 and 1/35 figures is negligeble since people come in all sizes as well.  

On a side note, I would wait and find a Dragon 1/35 OH-6A kit.  The old Revell 1/32kit  is really soft on details and has a bunch of oversized parts as well.  The Dragon one is 100 times better.

Thanks Gino.

No problem with keeping the "extras" in the same scale, the minigun set and figures (one has the M60) will all be 1/35.

Problem with the Dragon models kit is that it would be 8% smaller in the cabin area, and "those parts" that I'm putting in most of the kits I've currently got probably wouldn't fit. 1/32 might be a tight fit as it is for this Loach.

Basically if you imagine putting a box with the dimensions of (roughty) 35mm wide at one end, 25mm wide at the other end 55mm long and 35mm tall into the forward/engine area of a fuselage of any given helicopter kit then you'll see why I'm picky about the overall internal size of a model kit.

I think aside from the 1/35 Bell 47 (HTL-4) (which I know the parts fit in just right) and UH-1C I've got, the 1/72 Jolly Green and Sea King I've got will be a tight fit also, so I may end up just sealing them up and building them as normal.  The 1/48 UH-1D may get sealed up also but obviously as I've painted it already I can't do much about the seam.

Plus I've just bought the Revell Loach kit. Lol.

I'm not a rivet counter anyway, as long as it looks like a Loach I'm happy (yes I would have preferred a Dragon Little Bird but it's not available currently and just a little too small). I just don't want the crew/minigun looking odd if I use 1/35 versions of them, which it sounds like they won't because I doubt anyone can tell by eye there's an 8%ish difference.

Should be a good little (not very complicated) build at least, like the 1/35 Bell 47.  My Jolly Green has been fairly simple so far also but the Academy UH-1C is starting to give me nightmares, and so far I've only assembled the external weapons and the main body!!