I just purchased a '61 Penn Yan with a '58 V-4 Fat Fifty, It seemed to run OK except for this constant 'chunking' and then gears slipping and popping out of gear. The shift rod connector bolts seemed tight, but the rod was so far out of center, that I had to pry it over and was still hard to get a 1/4" drive wobble socket on it...I've never been into a lower unit before, where do I start... I noticed that the iboat marine store lower unit seal kit application chart doesn't go back to '58, should I try the oldest application available (mid 60's)? Much Thanks for any help.