[spareparts]

same basic long block, as far as i can tell even the same cam, the 180, 185, 485,190 were all the four barrel version(470,170,165 were the 2bbl). they jacked the power up to 190, then had to change the timing spec(pull them back to 4 degrees btdc) and fattened the carb up a little to make them live. Try and use one that has the 4 inch heat exchanger, radiator cap on the riser, and the delco style starter, they seem to be more plentiful and give better results. Check the riser and gasket real close, especially if it has the aluminum manifold. If a compresion test shows low compresion on #4, then it probably had a riser leak at some time.