[Tom63LeMans]

I have a ‘70 400 that was set up as a low boost blown street engine. It’s an interesting engine as it has heavily modified 1959 heads and early Weiand manifold and 671 blower. Assembly was discussed a while ago on this post; https://forums.maxperformanceinc.com...d.php?t=850881

I just took the crank to my machine shop with a newer style double keyed hub to have the second key machined in the crank. I was not aware but he informed that both keys in this hub are 1/4”. I saw some previous posts that recommended using two 1/4” keys. The question I have is how should the crank be machined for the key ways? Mainly what type of keyway and key is used for the primary key that positions the timing gear. Are they straight keyways instead of woodruff style.
I also have the hub that came with the engine that has a single 3/16” keyway. My preference is to be able to use either hub on the crank. I see that BDS offers hubs with both 3/16” & 1/4” keyways but I’d prefer to use what I already have.
Thanks in advance.