Which manufacturers and models are eligible for HTP?

Seriously thinking about a GT40 Mk1 for HTP. Which manufacturers chassis / bodywork are eligible for period GR? If this has been discussed before please link me to the thread.

Rick Muck- Mark IV

GT40s Sponsor
Are you looking to be in pre-1966 or post-1966 group? The Gelscoe chassis qualify as can Superformance with proper options and modifications. If you are looking to race in the US, several of the vintage organizations do not require FIA HTP but do have restrictions the chassis must meet. We have several Superformance chassis' competing in SVRA and HSR as well as other US based vintage groups. European vintage is a different kettle of fish and the FIA HTP is needed for most Euro groups.