L/71 Cam identification question

[Steve Antonucci]

I am currently working on a 427-435hp ( L/71 ) engine restoration.

I recently found a camshaft that I believe is a new - original L/71, L/72 or
L/78 and it has the following markings on it: on the back of the cam (top half)
is either 999006 or 900666. On the bottom half is 3143.

Is this "3143" an abridged part number for 3863143. If so, I believe that
this is the correct part number for the factory L/71 cam - isn't it?
Additionally, as this is a solid lifter camshaft, where can I get a correct
set of lifters? GM?

Thanks,
Steve

[Joe L.]

Re: L/71 Cam identification question

Steve----

Usually, original GM #3863143 cams will carry the casting number "3863144" and the casting symbol "OMO" between the lobes. However, I think that it's very possible that later GM SERVICE cams of this part number were manufactured from generic cores and, consequently, have none of the above markings actually cast into the core. The end stamping, as you describe, may have been the alternate means of identifying them. I have no idea what the 9-series number refers to, though.

The GM big block lifters, GM #5232695, have been discontinued for several years now. Over the past 5 years, or so, I've purchased several sets of them [none for sale] off eBay and "here-and-there". There may still be some "out there" if I haven't already got them all.

[Steve Antonucci]

Re: L/71 Cam identification question

Thanks Joe !

So, will another cam manufacturs solid lifters work?
I recently purchased a "correct grind" camshaft from
Comp Cams for a 69 L/78 restoration and I got lifters
as part of the set. Would it be OK to use these same
lifters, or should I look for GM lifters?

As always Joe, thanks.
Steve

[Joe L.]

Re: L/71 Cam identification question

Steve----

Lifters from other manufacturers will work fine. As a matter of fact, most of the mechanical lifters on the market today for Chevrolets are the "piddle valve" type which is the type that was originally used on all big blocks with solid lifters. I don't think that there's any problem, whatsoever, to using name-brand aftermarket lifters on a GM cam.

[Steve Antonucci]

Re: L/71 Cam identification question

Joe,
Here is a late addition to the cam question. I just noticed that the cam in
question has the groove on the rear journal like the 65-66 396 cams did.
Someone told me today that later crate engine cams came with the older style
grooved rear journal. Is this true? Now, the biggie: Can I install this
cam in a 1969 427 ( L/71 ) with the standard rear cam bearing, or do I need
to do something special because of the groove on the cam?

Thanks again Joe.
Steve

[Joe L.]

Re: L/71 Cam identification question

Steve-----

I don't know if the cams with the grooved rear bearing journal were installed in big block crate engines but I expect that they were. The grooved rear journal cams were sold in SERVICE for many years for all 1965-71 SHP applications.

You can use the grooved rear journal camshaft in a 1967+ big block. To do so you have to solder up the oil hole in the rear cam bearing and re-drill it to 1/16" diameter.

[Steve Antonucci]

Re: L/71 Cam identification question

Joe,

I'm a little spooked about messing with the bearing. My bad luck the solder
would break free & trash something. My luck seems to run that way. Can I use
a complete set of cam bearings from a 65-66 396 instead? Or, do any other
manufacturers offer the correct bearing(s) for this cam situation.
Steve

[Joe L.]

Re: L/71 Cam identification question

Steve-----

You absolutely CANNOT use the 65-66 rear cam bearing. The only bearing that you can use is the 67+ with the hole modified as I mentioned. I don't know of a manufacturer that makes a bearing for this conversion, but there may be one that I'm not aware of. Check with Durabond. Their specialty is cam bearings and they're the premium manufacturer of same.