Modern neoprene type seals for your Buick engine! Installation of these modern seals is much easier than the old style rope type seals, ensuring a positive seal every time. Front seals are housed in a steel retainer and are pressed into the timing cover. Rear seals are a two piece design and are a direct replacement for rope seals. All of our rear main seals are No Trim, Direct Fit, including our 400-430-455 piece, other suppliers offer a more difficult to use cut to fit seal. The use of neoprene seals will also free horsepower because the drag on the crank is only a fraction of that compared to rope seals.