I got my recently upgraded 360 to 390 back from the machine shop a couple of days ago and they already put the short block together. Somehow the crank key went missing in the last 6 months, so they manufactured another 1/4" key for me that they put on the crank. The problem I am having is the collar won't fit over the key. I took my micrometer out and the collar is only 3/16" wide in the channel. So I went to the junkyard where they pulled the crank for me thinking maybe the collar was different from my old 360 collar, but it was the exact same. What should I do, am I missing something?

 

I've been looking into this more... is it possible the junkyard that I bought the crank from gave me a 391 crank? What are the differences in the markings between the two? Does the 391 even have a 1/4" key?

 

Which key are you talking about and what collar?
There's two keys in the front of FE cranks, one for the timing gear and one for the balancer.

 

Balancer one. it's the collar that leads from the timing plate cover over the crank.

 

that's the part, found it online.

 

Take the key out, slide the spacer in place, then put the key back in the crank and install the balancer.
The slot in the spacer lines up with the smaller timing gear key, the larger 1/4" key is for the balancer only.

 

Thank you! You da man!

 

If it was a 391 crank, the spacer wouldn't even have fit on the crank snout