Will a regular motor gtubee gt5 fit? WITH a jackshaft?

Alright, i just got into motor bicycling and i just go myself a 29'er diamondback overdrive. Now, i am concerned a 66/80cc engine and a SBP jack shaft kit will not fit because of clearance issues. I really wish that it would fit because this bike would be a blast with all of its bells and whistles. From the back of the seat tube and the closest part it comes into contact with the knubbies would be roughly no more than 1 3/8''. And the frame of the bike is an XL (22'') but becauase of the bend in the down tube, it makes the frame a lot smaller. please let me know if you think that it would fit a slant head 66cc? and an SBP jackshaft. heres some pictures and videos and also is the specs of the bike on diamondback's website. thanks and i will appreciate all the help as i extremely need it.