if the kit you are looking at has a 98" wb it is probably a cobraette(sp?) which is a cobra style body on a corvette chassis.
An original Cobra and most replicas have a 90" WB and there are other variations with 92" 94" and 96" WB.
Here is a link to ERA's specifications.
http://www.erareplicas.com/427/specs.htm
These should be pretty accurate