Gentlemen, the non-clutch 5 blade fan was used on the Nova because the clutch fan would not fit in the space available. In 1968 the first BB Novas used the clutch fan setup like the Camaro...the short water pump allowed enough room for clearance. These stock 5 blade fans make an awful noise
thats why so many of them were canned back in the day and replaced with a flex fan....as for the smog tubes...my understanding is the transition from in front to over the valve cover took place in the fall of 69...may have something to do with the low profile intake...anyway I have discussed it with Bill Hodel and he can't say for sure the exact date of transition...for a fall 69 built car it's a toss up...
wilma