CORY CLAY

ok i have a couple questions.. and i did alot of searches and i didn't find any 1 with this problem.. ok i just put some new back rims and tires on my car ( converted lugnuts).. and after i was done i noticed a wobble from my rear tires and i could only feel it when coming to a stop or going under 20 miles per hour.. first i thought the tires were unbalenced so i took it to a tire shop today and they said the tires, rims were balanced and that the rear end was my problem ( or what they thought was the problem)... and they had it on the jack and turn the tires and a strange popping noise was coming from the rear-end.. but is this what's making my tires wobble? and it's so noticeable that people stopped me to tell me my tires were wobbling around... and it wasn't doing this at all when my other tires were on.. so i'm kinda stumpped on what's wrong..or what started this problem.. and another question is if it is the rear-end.. i have a 83 gs ( i think it has rear drum brakes) so i think it's a gs.. will this rear end work ok? or will it be to hard to do.. thier r no junkyards around here that have rx-7s ( search around for months).. and any advice or anything would be most helpful.. thanks again.
Cory
here is a pic of the rims

CORY CLAY

the pic wouldn't work... cause i already used it in my other post " good deal?"....

CORY CLAY

o yea i have a 84 gsl.. just to let u know