About half the hot rod parts I've purchased in my life have been "too big"! It is a nature of the beast. I think everyone buys stuff to make power then they start driving the car and decide that they don't really need all of the go fast stuff. Smaller usually works better for both carbs and cams although going big on the cubic inches is usually a win. Chevy hit a home run with their 502 crate engine by making it big but putting a really small cam in it. Lots of street rod guys love that engine. Just drop it in and drive it.