Ken,

When you put in the MSD was it just the coil replacement, or the full thing? I've heard that on our 75 HEI you can get really good benifit from just changing the coil and adding a kit for new springs and vaccume lock.

Just curious which you did?

I already have the billet ready to run distributor and coil. I just ordered the MSD 6AL. This is a good combo correct? I 6AL will be here tomorrow, and I will install it Thurs.

Any comments?

Oh no.  Actually if you have the Billet MSD ready to run distributor, then the 6AL will not work...... maybe.  The ready to runs were designed to be used without a CD ignition box.  Thats the reason for the module installed in the distributor, like the more modern GM computer controlled distributors.  I say maybe, because I believe you can bypass the module, but you will need to contact MSD tech to get the scoop.  They may just tell you to use the HEI wire hook up on the box instead of the Green and Viloet wires coming out of it.  I'm sure there is a way to make it work, but if anyone else is considering running a 6AL box and plan to install a new MSD distributor with it, make sure its a magnetic pickup style, because the install is much easier.

AfterShark- I think Jegs mixed me up on this one . They told me the dist. doesn't need the control box, but you can upgrade later without a problem. Supposedly the PN# 8360 plugs directly into the PN #6420. I see a diagram that came with both parts saying just to bypass the magnetic pick-up.

 I edited this post because I didn't have proper info. I had a family emergency today and won't be able to install it till next week. I will reread the old posts, when I get a chance.