Hi And welcome.
When you say "Where can I get one" do you mean the engine or the whole completed car or the kit?
For the engines just do a search on the net and depending whether you want to buy from a UK supplier or you are prepared to buy from overseas (USA) and would this be a "Turn Key" ( Ready to run) engine or one that you are going to build yourself.
For a completed car you could check out the classifieds on this website or visit Hallmark cars or Sovereign cars or even buy one from a specialist builder....................Like me
If you are going to build it yourself then you need to go and visit the manufacturers, which if you are looking at Jaguar based (Which you will need to if you are into Chevy 502's) and there are 3 main players in this sector:-
Dax. 01279 442661 (Harlow)
GD. 01949 843299 (Nottingham)
AK. 01733 267633 (Peterborough)
Happy hunting.
Everyone else. HOW DIPLOMATIC WAS THAT