▁alter ed ▁aer od ynam ics : ▁the ▁water ▁p ump ▁pul ley ▁was ▁unders ized , ▁so ▁it ▁was ▁spin ning ▁too ▁fast ▁and ▁causing ▁cav itation ; ▁also ▁the ▁header ▁tank ▁was ▁in ▁front ▁of ▁the ▁passenger - side ▁bulk head , ▁far ▁from ▁the ▁radi ator , ▁and ▁the ▁tub ing ▁diameter ▁was ▁too ▁small ▁at ▁ 7 / 8 ▁in ch . ▁With ▁the ▁p ump ▁pul ley ▁en larg ed , ▁and ▁the ▁tub ing ▁increased ▁to ▁ 1 ▁ 1 / 4 ▁in ch , ▁the ▁problem ▁was ▁elimin ated . ▁The ▁main ▁draw back ▁of ▁the ▁new ▁body ▁shape ▁was ▁that ▁it ▁reduced ▁down force ▁on ▁the ▁tail ▁to ▁the ▁extent ▁that ▁it ▁caused ▁lift ▁and ▁direction al ▁inst ability ▁at ▁spe eds ▁over ▁ ▁on ▁the ▁M uls anne ▁Stra ight . ▁These ▁cars ▁had ▁ch ass is ▁numbers ▁X K C ▁ 0 0 1 , ▁ 0 0 2 ▁and ▁ 0 1 1 . ▁The ▁first ▁two ▁were ▁dis m ant led ▁at ▁the ▁factory , ▁and ▁the ▁third ▁surv ives ▁in ▁normal ▁C - type ▁form . ▁ ▁In ▁ 1 9 5 3 , ▁C - Types ▁won ▁again , ▁and ▁also ▁placed ▁ ▁second ▁and ▁fourth . ▁This ▁time ▁the ▁body ▁was ▁in ▁th inner , ▁l ighter ▁al umin ium ▁and ▁the ▁original ▁tw in ▁H 8 ▁sand ▁cast ▁SU ▁car b ure tt ors ▁were ▁replaced ▁by ▁three ▁D CO 3 ▁ 4 0 mm ▁Web ers