2 stroke kit for an oblong down tube?

This is my first build, so please be gentle.

I picked up a Huffy Savannah 700c yesterday for about the price of a set of bike tires. Before buying it I did a google and found this example so it must be possible to motorize:



Here are the dimensions of the tubes:



I'm thinking of buying this motor kit:

80cc Silver Slant Bicycle Engine Kit

My question is, will this motor fit on my frame? Looking at the first photo, I see he's gone with a slant head and it doesn't look like he's using any special / custom mounts. I don't know what motor he's using. Any thoughts or suggestions? Incidentally, I'm not married to buying the kit from Raw nor that particular kit, any reputable dealer and kit is fine.

*BUMP*

I'd really like some help with this. Shipping is so high for these motors that if I order the wrong one it's going to be an expensive mistake.

Thanks Nougat. If you look at the very first picture and zoom it in, you'll see that no adapter was used. What I don't know is if all the 49/66cc engines have the same mount and if not, what engine did he use?

Got it, thanks!