How to change your 1966 Ford Mustang inline 6 into a 200ci v6?

I want to know how much it would be, what parts I need to get, how to put it together, any answer would help me out thanks

A classic Mustang is worth more if it is original. Leave the original engine alone unless that engine is completely shot. If that is the case, either rebuild it ( to keep the numbers original ) or replace it with another I6 engine.

It's all ready 200ci and there's honestly no practical reason or benefit to rebuilding it as a V6 just for the hell of it. As said it's worth more as is, and since mustangs didn't have V6's until 1974 so if you put one in that might be a problem for a lot of people when trying to show off or sell it. So just leave it alone and save the money

The transmission & the rear-end are geared for the straight six.