904 AMC gearset swap.....

I believe you need the sun gear that the front planetary slips onto as well as the front planetary gearset and that's it. I'm not real familiar with 904's/999's like I am with 727's but in 76 (and again in 90) 727's changed the spline angle on the front planetaries so you have to mate them with the correct output shaft. Maybe Zijmer would know if 904's are like 727's in that respect? I'm not positive but think the o.d. ratio of a A500/A518 is .70