1. ENGINES WHICH ARE STANDARD BORE MUST USE STOCK POSITIONS. ENGINES MAY BE BORED TO A MAXIMUM OF .040 OVER THE STANDARD BORE SIZE. STOCK TYPE CAST ALUMINUM DISHED PISTONS, WITH A MINIMUM RECESS OF .040 MUST BE USED IN ANY ENGINE WITH AN OVERBORE. ALL ENGINES, INCLUDING THOSE THAT ARE OVERBORED FROM STANDARD SIZE MUST STILL ADHERE TO THE MAXIMUM COMPRESSION RULE. 9.5 TO 1 COMPRESSION RATIO,150 COMPRESSION MAXIMUM. NO INTERMARRIGE OF RODS OR CRANKSHIFTS TO BLOCKS ALLOWED 2. THE ENGINE MUST BE THE SAME MAKE AS THE CHASSIS. GM TO GM, FORD TO FORD-MERCURY-LINCOLN OR MOPAR TO DODGE-CHRYSLER-PLYMOTH. MUST BE MOUNTED IN THE STOCK LOCATION. STOCK CAMS ONLY!! 3. MOTORS: 307 OLDS,305 CHEVY,302 FORD, AND 318 MOPARS ONLY NO FUEL INJECTION STOCK APPEARING OIL PANS,NO KICK OUTS 410 LIFT RULE + OR - 10 NO ANGLE MILLING OR PERFORMANCE ENHANCING WORK ON HEADS OR BLOCKS. BLOCKS MAY NOT BE DECKED STOCK HEADS ONLY. NO VORTEX HEADS NO GRINDING OF ANY CASTINGS. CASTING MARKS AND NUMBERS MAY NOT BE REMOVED. VALVE SIZE MUST MATCH HEAD USED. 1.86 VALVE MAXIMUM, 1.5 EXHAUST MAXIMUM. NO MORE THAN .40 VALVE SHIMS ALLOWED TO OBTAIN STOCK VALVE HEIGHT. NO INTERCHANGING OF ROCKER ARMS, RATIOS. NO SCREW IN STUDS. NO ROLLER CAMS. STOCK BALANCER ONLY, AFTERMARKET BALANCER ALLOWED BUT MUST BE MINIMUM OF 6 3/4" IN DIAMETER AND 1 3/8" IN WIDTH/THICKNESS. NO LIGHTENING OF BALANCER. NO ALUMINUM BALANCERS ALLOWED STOCK IGNITION ONLY(STOCK WORKING ORDER) NO AFTERMARKET IGNITION ALLOWED. O.E.M. DISTRIBUTOR ONLY. NO CENTER DUMP MANIFOLDS. MUST BE CAST IRON ONLY. NO FACTORY O.E.M. OR AFTERMARKET TYPE OF HEADER ALLOWED. NO 1987 OR NEWER TRUCK MANIFOLD ALLOWED. EXHAUST MUST EXTEND BEYOND THE DRIVER'S SEAT. OVAL OFFSET MUFFLER ONLY. NO CLAMPS,MUFFLER MUST BE WELDED.