8) about the only parts from the 170 you cant use are things like pistons, and crankshafts. the connecting rods are all the same size 144-200. if your distributor uses a 5/16 oil pump drive shaft then you can use it in the 200. the cylinder heads all interchange, though you have to deal with chamber volume and port and log sizes. valve covers, oil pans, camshafts, lifters, timing covers, flywheels/flexplates, vibration dampners, pulleys, accessory brackets, all interchange.