I always liked the Black Gold puller from the 80's, so if I build one, it will probably be similar to it. Someone built a 2wdpuller that was in RC Car action back in the day that was really cool. It had a clod body, clod rear tires, and buggy champ fronts. It would be cool to re-produce that one just because how cool it was. Thanks for the info on the springs. I will get with you before too long about building one up.