Among the dragsters and Indy cars, there are two series that supply most of the versions for these castings:

• Dragsters USA series.  There are 11 castings in the series and they feature various drag racing teams.  6 of the castings are very fast and the others are duds.  The less competitive cars are either too narrow and/or too light to be fast.  All of these dragsters feature the "Racer's Edge Speed Wheels".  These wheels feature a thin raised "lip" on the the inside of the wheel which means there is less tire surface touching the track.  This supposedly creates less friction.  These wheels were later used in other models.
• The Indy Race Car Winners.  There were 8 replicas of different Indy winners produced spanning the years of 1969 through 1992.  5 of them are very fast (in top three tiers), one is competitive and the other two are just ok.  I have several of each car, as I keep thinking the two slower versions (1977 and 1992) must be faster.   Note that the corresponding pace car was also released in a two pack with the Indy winner.  See blister above.  These cars are also very fast.

Elite Speed
Top Tier

1971 Dodge Charger Funny Car
2001, Kay Bee 5 Pack
57 grams, Casting #322
Very fast funny car.  This dragster version was actually not from the Dragsters USA series, but found in a Kay Bee 5 pack.  Featuring Racer's Edge Speed Wheels.

1972 Dodge Charger Funny Car
1995, Dragsters USA series
53 grams, Casting #332
One of four Elite level dragsters from Johnny Lightning.  This 1972 funny car is represented by "Wild Willie Borsch",  Featuring Racer's Edge Speed Wheels.

1978 Indy Car
1996, Indy Race Car Winners
39 grams, Casting #456
The fastest of the Indy cars.  It's also among the fastest cars under 40 grams.  The good wheels and low center of gravity contributes to the speed.  Featuring Racer's Edge Speed Wheels.

1971 Ford Mustang Funny Car
1995, Dragsters USA series
55 grams, Casting #323
This is the "Blue Max" version of the '71 Ford Mustang Funny Car.  This is the third fastest of the dragster castings.  Featuring Racer's Edge Speed Wheels.

1971 Chevy Vega Funny Car
1995, Dragsters USA series
58 grams, Casting #325
This "Barry Setzer" version of the '71 Chevy Vega Funny Car is known to be a fast racer.  This was my fourth fastest casting in the 11 car series.  Featuring Racer's Edge Speed Wheels.

High Speed
2nd Tier

The Indy Car Winners series features a number of fast cars.  See blister pack example above.

Car	Year, Series	Casting Number
1979 Indy Car	1996, Indy Car Winners	457
1970 Indy Car	1996, Indy Car Winners	452
1974 Indy Car	1996, Indy Car Winners	453

Good Speed
3rd Tier

Some other fast cars include the 1972 Dodge Challenger Funny Car and the 1971 Dodge Demon Funny Car, both from the Dragster series.  Plus the 1975 Indy Car.

The small 1969 Indy car is competitive.