1968 z28 cam shaft

[sd1968z28]

i am getting my original 302 rebuilt and was wondering what cam shaft to install.  i have both the original grind part 3849346 and the off road 3927140 at my disposal.  i have the offroad cam in the ce engine in the car now and i love the sound, any suggestions?

[Jerry@CHP]

Either is good.  If you tighten the valves on the 30-30 cam it will sound more radical.  The 30-30 cam builds more cylinder pressure which can make more horsepower in some cases.  In many cases, bigger is not always better.

JM

[sd1968z28]

ok now i just have to beat one out of my brother!

[sd1968z28]

he wants $165.00 for cam, lifters, and springs.  pretty fair price?

[JohnZ]

he wants $165.00 for cam, lifters, and springs.  pretty fair price?

Is that new, or used? The "30-30" is also available as a kit (cam and lifters) from GM (manufactured by Crane) and from Federal-Mogul/Speed-Pro for around $150.00.

[fireZ]

I always use the Federal mogul/Speedpro cam. I tighten the valves a little more like Jerry says and the car runs as strong as any 302 car  I have been in. Listen to Jerry and you will never be so happy.

[sd1968z28]

brand new nos gm parts

[JohnZ]

brand new nos gm parts

Sounds good to me. Don't use aftermarket "Godzilla" springs or the GM #3927142 springs - those are for the "-140" 2nd-design off-road cam. The "30-30" production cam used ordinary #3911068 springs (80#/200#); that's the beauty of the "soft-touch" GM ramp profile - it didn't require excessive spring pressure and had excellent reliability.

[sd1968z28]

i am thinking of going with the 140 cam, he has both and i love the sound of the 302 i have with it now, a little doggy on the bottom end but above 5000 rpm it screams all the way to 7500. i haven't had the balls to go higher but it still seems to be pulling.  maybe since i am going to replace this engine anyway i should test it's limits?

[sam]

Yea! Wind it up a little!

[Jerry@CHP]

We take my 302 stock eliminator engines to 8200 on the dyno.  My data logger tells me that I've had the car to 8600 on the rev limiter chip.  The rocker arms are always the weakest link, but the "O" rockers hold up very well.  The Manley 43140s are very good too.

Jerry

[sd1968z28]

i just got back from thrashing my z28, great fun.  i think it needs new plugs finally it cleaned out ran pretty good but not 8600 good,  holy cow thats clipping!  my 383 race motor only sees 8000 rpm and its roller everything with 45 pound kriptinite crank!