One of the most popular marques among antique-tractor collectors and restorers is Allis-Chalmers. This all-new guide reviews the most collectible Allis-Chalmers tractors and crawlers ever built, tackling by year of manufacture landmark machines like the Model 20-35, Model U, Model M crawler and Model G. Exclusive photography accompanies complete descriptions of basic model options, specifications, components, paint codes, serial numbers, design changes and promotional literature, while a price guide advises readers on what to look for in each model. Brief model histories and descriptions of common repair and restoration needs round out this complete reference for the legions of old-tractor enthusiasts.