Weber 40's slot in or bolt on trumpets?

[novathere]

What ones do I need? Came with bolt on but venturis move is this normal? Also can anyone confirm what ones these are? http://uploads.tapatalk-cdn.com/20160324/a94a25c3766e140f464f838aade8e245.jpghttp://uploads.tapatalk-cdn.com/20160324/2c4edd8f2875bac4e70b1a58443e0810.jpg

[novathere]

http://uploads.tapatalk-cdn.com/20160324/67ffcdbde72354ee16e6a1010b4bb860.jpghttp://uploads.tapatalk-cdn.com/20160324/64847414e6034bb9e166784c57831f64.jpghttp://uploads.tapatalk-cdn.com/20160324/71cc64ed0e1e472d90092078e33bfe1b.jpg

[Royston]

Venturis slide in but there are held in place with a small clip in the slot, should only be a small amount of movement.

I see there are nylok nut retaining the trumpets, good idea, I have seen the damage a nut can do when drawn through into the engine!!