With the timing gears and distributor being new there is room for error so go back and double check the TDC is not 180º out or just wrong. If you don't find anything there check the firing order. Still good, pull the valve covers, spark plugs and dizzy cap. Turn it over slowly by hand and watch for signs of illness @ the dizzy post and valve trains. If the timing set/dizzy/firing order are in order then you may have a huge vac leak or serious valve related issues. IMO