Originally Posted by
SS LS1
Not the answer you want to hear but drop the aluminum knuckles and keep the Tamiya axles as they are the best (most durable) IMO. Seen too many problems with aftermarket axles that I will only run the Tamiya pieces. If you must run the aluminum knuckles then clearance them with a Dremel to work with the stock Tamiya axles and you will likely not have any axle reliability issues.
Thanks that's actually the answer I was expecting. As the aluminum knuckles were only $14 I'd rather not spend another $37 on the Spec.R axles hoping they fit. I like the Dremel idea and I may try it for future use (if I ever break the Tamiya knuckle and need a replacement in a pinch).