insurance help!

[mysticclam]

While on the subject of insurance, I do alright on my 98 stang with the two vehicle thing but my 80 mustangs 6 cyl is just about dead. I was going to drop in 302 but the insurance company tells me they wont cover it because its a modified vehicle. Anyone else have any dealings with this? I figure Ill be putting in another late 70s - early 80s lo po v8 that was optional in the car stock. If it was just performance mods i might must not tell them, but if something happened and the insurance co really didnt want to pay, they might look hard enough to notice a different engine. Anyone know of a place that deals in insuring "modified vehicles?"