I have a '74 914 that's 95% rust free. I bought the car specifically to install a small block Chevy V8. I'm getting my parts from Las Vegas from a company called Renegade Hybrids. I plan on having the parts needed and installing the engine in a few months. Their webpage is
http://www.renegadehybrids.com and they do V8 conversions for other Porsche models as well. I chose the 914 for the mid-engine design, and the fact you don't ever see them on the road. The project will be relatively inexpensive sinse a 300 horse 914 can't be outrun or outhandled by very many cars out there. The engine ran for a month after I bought the car, and it was a blast ripping around the corners even though bicycles could outrun me from a stoplight with the 1.8L 4 cylinder in the car at the time. I live in California, and the smog laws are any model 1975 or older is not required to pass smog. Yes, that is my car pictured below.
Don't let anyone tell you it's the wrong path to go V8 in a 914 as long as you deal with Renegade Hybrids. They've been in the business for a long time, and have the bugs worked out. I believe they are at Laguna Seca today trying out their 500 horse 914 on the track there.