Here's mine at El Mirage last November. It is a P-38. 36" diameter and it started out at 12'8" long. I added 20" to the length and it was still quite an exersize in packaging. Try this. Put on a -20 fire suit. Now measure the width of your shoulders. OK. Now build a roll structure out side of that. Don't forget that sooner or later you're going to want to get out of the Racer. Like Ronnie says, all of the "little" things add up very fast. I've seen a number of people start build with a 24" Tank and give up. Bobby Green's Tank is 30 or 32" and I really don't think I'd want to go any smaller than that. If it's any help, I've just started producing 1/8 scale P-38 Tanks that could be a help in planning. PM me. I'll take care of Ryan if anyone buys one. I'm fairly certain Beatty's Tank was full size. Wayno