Trying out a spreadbore carb on the Duster.

All Carter/Edel carbs are great carbs. See below. Carter 625 AFB v 600 Hol. Carter made more tq & hp.....& used less fuel doing it.

Spread bore. The term appeared when the QJ appeared in the mid 60s. To accommodate the huge 2.25" sec t/blades, the c/line of the t/bores had to be 'spread'. Hence the name.

I doubt whether an AFB, AVS or TQ will seal to that manifold without a spacer. There is very little flange metal left on the sides & rear of that intake to seal without an air leak. May fit without a spacer/adapter, would need careful checking.

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Edelbrock makes like a 1/16" plate that will seal it fine. No need for a thick adapter or spacer.