Must be close to 6 feet long or more. Look under it and you'll see one of his Crackerboxes for comparison.
Another shot....

Careful with that engine making radio noise. I used the exact same one in a 60" cat. I even converted it to water cooled just like your pics. I could not get it to run consistantly without MASSIVE radio interferance. I hope you can find a resister plug and have better luck than I did.

That thing is prety big.The Easy Vee in the background is even a better comparison of its size. Good candidate for twins!