insurance blues

[mysticclam]

I am putting a 302 into my 1980 mustang to replace the all but dead 200 six. My insurance agent told me they couldnt write a policy on it because its "modified" I think thats rediculous as the engine going in is one offered in the car in the first place. So, anyone know of a good place that will sell insurance for "modified" vehicles.
I dont want to just lie and say its still a 6 you never know when an adjuster will look under the hood and go oh, you lied, your insurance is void after you've been in an accident.

Thanks for any ideas
-Tim