Carb adapters 4 hole vs. open

[PAJEEPER]

I want to go with an aftermarket carb but keep my spreadbore motorcraft style manifold. Which is better 4 hole or open? I don't want to lose too much torque the truck will be mostly hauling/towing.

[mrclean]

I would go with the four hole. It will keep the mixture velocity high for more torque and better throttle response.

[bigwillys]

I agree with mrclean, the 4-hole has a higer air velocity, and will give you more or the performance you want. Edielbrock actually says NOT to use open adapters with performer series carbs, problably for this reason.

[Bob Barry]

I just did a writeup on my tech page about the peculiarities of adapting other carbs to the 4350 intake:

http://home.off-road.com/~wagoneer/tech/carb/4350_compared.html

That might help you out a bit.