Should have to problems with the gears you mentioned. Should fit just fine. In nearly 41 years of turning wrenches its one of the few things I never really messed with except once on a Surburban and it came out fine. Just had to help change the pumpkin. The 327 is a great engine. Being it is a built one 4.10 or 4.56 will work just fine. The 4.10 will give you some highway cruising abilities without revving too high at 60 or so. I wish you success at your project. I buy stuff from Ebay. Have had good success with them. Henry
