I do not have any experience with either however found this interesting tidbit online, The 430 429.69-cubic-inch (7,041.4 cc) 430 was produced from 1967 to 1969. This engine had a bore of 4.1875 in (106.4 mm) and a stroke of 3.90 in (99.1 mm). This engine was used in B-, C- and E-body (large body) Buicks. Most parts except the pistons interchange with the 400 and 455. The 455.72-cubic-inch (7,467.9 cc) 455 Buick V8 used a 4.312 in bore and 3.90 in stroke. It was produced from 1970 to 1976 and was based on the 400/430 V8. The regular Buick 455 was rated at 350 hp (261 kW), while the 455 Stage 1 was underrated at 360 hp (269 kW). In all actuality, the Stage 1 produced around 425 hp (317 kW). The regular 455 produced a rated 510 ft·lbf (690 N·m) of torque, more than any other muscle car engine, and second only to Cadillac. The hp was somewhat reduced in 1971, mainly due to the reduction in cylinder compression ratio in order to cope with the introduction of new federal laws requiring new cars to use unleaded gasoline in an effort to reduce exhaust emissions, then, on paper, considerably reduced to approximately 250 hp (190 kW) starting in 1972, due to the new measurement of horsepower as SAE Net horsepower rather than a gross horsepower rating. Tightening emissions controls caused the engine to drop in power, a little at a time, through 1976. Most parts except the pistons interchange with the 400 and 430. The 455 was one of the first "thin-wall casting" engine blocks, and weighs significantly less than other engines of comparable size (for example, 150 lb (68 kg) less than a Chevrolet 454).