426 Hemi

Is #54 lower performance and #71 high performance?

Thanks in advance.

tbarb

The #54 stamped on the autocam at the top of the mainshaft is typical of the 1963 tach drive advance curve. I believe this same curve was used on the low hp and the high hp engines.

In 1964 I believe #54 may be used on the low hp and a different # with a more aggressive curve on the high hp engine.

I can't help with the #71 autocam.

65tripleblack

There were numerous autocams used with tach drive distributors; probably 10 or more for Corvettes through the years.
Wayne Midkiff in NCRS is your go-to guy.
You can also ask Dave Fiedler of TI Specialty.

Here are just a few:

I THINK that the "03" was for the 365/375 engines, and the "54" was for the 300 engine. The "247" , I THINK was for one of the 454 engines.

426 Hemi

Thanks for the info guys. They sure made a bunch of different ones/shapes!

Went out and looked at a few tach drives I have. A new '62 dual point---it has the 54. Then there are these two that I have no idea what engine---71 and 165. Of course they were marked on the bottom of the cam:

tbarb

I would not swear to it but I think the 165 is for the 66-67-68 low hp engine. I can almost remember seeing that # when I had my 67 300hp distributor apart.