An even bigger difference is the driver set-back advantage of the Altered Roadsters over the Street Roadsters. In Street Roadster, the driver must not sit back out of the stock passenger compartment. In Gas and Fuel Roadsters, the driver can be farther rearward, allowing the driver to get down out of the air.
The Dodge Boys with their V4F car set Street, Gas and Fuel Roadster records at one meet a couple of years ago. You can search for them here.
Stan