According to the MoPAR parts book 55-58 a 17 gallon tank for 55-56 Plymouth and Dodges was part #1557 468,all except Suburbans,a 20 gallon tanks was for 55-56 Plymouths and 56 Dodge(not 55) for all except Suburbans and D62 (whatever that is),part #1632 823,hope this helps Ron.Thanks again and thank Wendy for us again. Adam |