I just had my 305 rebuilt and now it seems a lot more tame than it used to be. It sounds different at idle (meeker) than it used to and well, it doesn't perform very well now. It actually has to downshift to move out where a slight throttle nudge used to send it moving out. My manual says there were two camshafts used in the 305 one with Intake elevation of .269 and an Exhaust of .276 and a milder one with an Intake elevation of .234 and an exhaust of ..257. Would such a small change make a big difference? I wonder if the guy who rebuilt it put the milder one in by mistake. How can I tell. The guy said he didn't know that it's the only one that comes with the 305 rebuild kit.

 

What kind of cams are these? Do you have any part numbers?

The numbers you give don't make much sense, if you could find out anything else it would help.

 

The second one you listed is the legendary LG4/L03 "peanut" cam. That's the one you had. The "H" motor is the LG4.

The first one was the L69 cam. You didn't have that one.

More likely, they put in a "929" replica; that POS seems to end up in about 99% of all rebuilds where the customer doesn't specify exactly what he wants by part #, or supply it himself. On paper it looks like more cam than the "peanut" one; but the esults are always a disappointment.

 

Damn, i knew the LG4 cam was small but not .351", .39"! The 929 cam is .39", .410".

 

I talked to the guy at Dave's machine shop (who built my 305) He said he never even heard of the 234 cam (peanut cam) and used a standard 274 cam from 350 rebuild kits. After advancing the timing and raising the idle, My Z-28 sounds and runs great!
We set the timing 6 degrees advanced with the computer connector unplugged. The throttle response now is excellent! I can wait to get those SLP headers on there and see how that improves things.

 

So that means it's the 929 cam. Yuck. The one that was used in all the 165-180 HP wonders of the 70s.

Look up the specs of the cam he used; if it's .390"/.410" (.410" valve lift is .274" lobe lift with 1.5 rockers BTW, sounds suspiciously like a match), 194°/204° @ .050", then that's what you've got. Eeeeewwwwwww.

You could get it to actually run good by putting something decent in there instead of that.

 

I have a 929 cam in my 305. All the CFI LU5 cars did.

 

I'm pretty happy with whatever cam it is . It runs better now than it did before the rebuild, idles strong and supports my air-conditioning during these hot California summers. I think it will get around 20 mpg on the freeway too. Anything lumpier might upset the computer or move the peak torque band around somewhere strange. I don't WOT it very often.