THE PLT DEPARTED KENDALLVILLE, IN, AT ABOUT 1800 EST & MADE A REFUELING STOP AT TOPEKA, KS. AT TOPEKA, HE OBTAINED A WX BRIEFING FOR A FLT TO PUEBLO, CO, HIS INTENDED DESTINATION, & WAS ADVISED OF MARGINAL VFR TO IFR CONDITIONS ON HIS PROPOSED ROUTE. HE THEN ASKED ABOUT THE WX ON THE FOLLOWING DAY & WAS TOLD THAT IT WOULD BE MARGINAL VFR TO VFR AFTER 1500 HRS ON 3/31/84. AT THAT TIME, HE TOLD THE BRIEFER THAT HE WOULD 'JUST SIT ON IT.' HOWEVER, THE PLT TOOK OFF. LATER, HE CALLED SALINA RADIO & OBTAINED THE SALINA & PUEBLO CURRENT & FORCAST WX, WHICH WAS MARGINAL VFR TO IFR. AFTER THAT, THERE WAS NO FURTHER RADIO CONTACT WITH ATC. ON 4/2/84, THE ACFT WAS FOUND APRX 1-1/2 MI SOUTHEAST OF THE GARDEN CITY MUNI ARPT. AN EXAM REVEALED THAT IT HAD CRASHED ON A HEADING OF APRX 120 DEG WITH THE LANDING GEAR EXTENDED. IMPACT OCCURRED ON LEVEL TERRAIN WHILE THE ACFT WAS IN A RIGHT BANK. NO PREIMPACT FAILURES OR MALFUNCTIONS WERE FOUND. THE 0030 CST WX AT GARDEN CITY WAS: 200 FT OBSCURED, 1 MI VIS WITH LGT SNW, TEMP/DEW POINT 33/31, WIND 110 DEG AT 8 KTS.