Independent field notes for a better-documented collection. Sources and further reading are linked below.
The short answer: look beyond the badge
The GT500KR brought the 428 Cobra Jet to the 1968 Shelby lineup. KR stands for King of the Road. Shelby American’s own retrospective links the new name to that engine change; Newport Car Museum describes the KR as a mid-year introduction based on the GT500. The earlier GT500 used the 428 Police Interceptor. Both names belong in a discussion of 1968 Shelbys, but they should not be treated as interchangeable.
Why displacement is not enough
A listing that says “428 V8” has not answered the whole question. Ask which engine specification is claimed, what documentation supports the claim, and whether the installed engine is represented as original or a replacement. Newport’s account describes the Cobra Jet’s improved-breathing heads and larger exhaust manifolds. An engine’s current appearance, however, cannot establish the complete history of the car around it.
Keep three questions separate in your notes: what the car was built as, what equipment it carries today, and what documents connect those two states. A well-documented replacement can be easier to understand than an unexplained claim of originality. Neither a photograph nor this article replaces an inspection.
Compare like with like in the market
Start a comparison sheet with model, body style, transmission, sale date and price category. Then record restoration history and the evidence offered for originality. Do not use a convertible result as an automatic valuation for a fastback, or an asking price as a completed sale. These distinctions matter before you try to explain a difference in price.
For each comparable, keep the original listing URL. A cropped social-media screenshot may omit a reserve-not-met result, a later correction or an important disclosure. Follow the full record instead of collecting only the headline number.
Make your next search more precise
Try “1968 Shelby GT500KR” with a body style or a complete VIN rather than “Shelby 428” alone. In KR68, open the individual vehicle record and follow its public sources. The registry tracks documented chassis; it does not certify an engine, authenticate a car or guarantee that a past listing is still available.
Sources & further reading
Public sources checked November 6, 2026. Seller-submitted descriptions and documents are attributed to their listings; KR68 has not independently inspected these cars.