 Further proposals based on the delta wing resulted in two versions of the design known as C104 : the single engine C104 / 4 and twin @-@ engined C104 / 2 . The designs were otherwise similar , using a low @-@ mounted delta @-@ wing ; the primary advantages of the C104 / 2 were a larger overall size which offered a much larger internal weapons bay , at the time a cutting @-@ edge feature in a fighter , and gave it twin @-@ engine reliability . The proposals were submitted to the RCAF in June 1952 . 
