Bob, Due to the other problems of the D's, I'm recomend at least a 850cc amps battery. I use Champion from Sam's at $59.95 and a full 2 yrs repl. Your car will love the reserve power it will store and so will you when you need it.If you make some of the mod's in the future you will need it. Aternators love lot's of power to charge the battery and if you haven't converted to a higher amp alternator then you will need it. my $0.02c's worth John 11004