liberty hemi 4 speed

well after 15 years of waiting for this liberty hemi 4 speed the guy just gives it to me. he had it behind a bbc in a vega. so i am now on the hunt for a 18 spline input for a mopar. this is a aluminium case a body style trans it came from libertys just for drag racing. any one know were to start looking. i have seen them on ebay as stock replacements for 875.00. i am still going to use it for racing so would like to find just the input in good used condition. this will let me put my doug nash in my new race car. i will probably call liberty monday to see what they got. any help is appreciated