Show us a picture of the engine. If the distributor is in the front and angled to the passenger side you have a B or RB engine. B engine being a 350/361/383/400 or RB being a one rear only 383, 413, 426 Wedge and 440. If the distributor is to the rear you have a LA (273, 318, 340 or 360). If the engine is leaning to the passenger side and long than you have a Slant 6.
