You may want to compare the 2 manifolds for bolt holes for mounting carb. linkage ect.
The original manifold on my 57 270 coe has been brazed on before. The PO gave me another manifold with the truck.
Then I noticed mine has threaded bolt holes for my carb. linkage and the one he gave me does not have any.
Mine runs great with the welded manifold, so I guess it will stay on the truck.

57 GMC LCF 370
55 John Deere 40-W
59 John Deere 430-W
2000 GMC 4x4
56 John Deere 420-W
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