I would recommend putting a Mustang II front end in your 51 chevy; Its a fairly easy install if you know a little about fabrication. The parts to do the conversion are readily available and cheap. While I was at SEMA I saw a new company called Helix that is offering a u weld mustang II front end kit and it is very inexpensive. It looks like very nice quality and made from 3/16" steel. It is a universal kit that includes instructions how to measure your frame and notch the pieces accordingly; so if you have a welder you can do it. they come with step by step instructions with pictures. Dollar for Dollar this is the best kit i've seen recently. if you use a camaro or nova clip it will widen your track width and make the car look funny in my opinion. The width from wheel mounting surface is over 2" wider than your stock width, so your front tires won't tuck under the fenders like they should and they will stick out.

I went to the Helix website and it's not completely up yet, but you could probably give them a call from the number listed.

http://www.thehoffmangroup.com/helix/