[Seattle Sam]

Thanks for all the responses, I would pity the fool that puts an L88 cam into a 396 with cast iron exhaust! [img]/ubbthreads/images/graemlins/no.gif[/img] [img]/ubbthreads/images/graemlins/eek.gif[/img] [img]/ubbthreads/images/graemlins/no.gif[/img]

At least, I will be sticking with the 143 cam. My goal is to blueprint the motor when I pull it out, and do a few things to improve air flow (like port matching the manifolds). I plan to drive this car on the street a lot, but I would also like to see 12's on bias-ply tires with it..

Seriously, I started looking at the specs as listed in the Chevrolet by the numbers book, and the L88 and ZL1 have tons more duration than the L72/L78 cam, as well as more lift.

Lift and duration, per Chevrolet by the numbers 1965-69 These must be at 0.000" lift..

L72/78 cam, pn 3863143, lift .520 intake and exhaust, duration 316 degrees intake 302 degrees exhaust.
L88 cam, pn 3928909, lift .562 intake, .584 exhaust, duration 354 degr intake, 360 degr exhaust
ZL1 cam, pn 3959180, lift .579 intake, .620 exhaust, duration 354 degr intake, 360 degr exhaust

I do have a question about the duration of the 143 cam, Chev by the numbers lists duration (from .000 lift I assume) as 316 / 302, the aftermarket cam sellers list their "143" cams as having 240 deg of duration for both intake and exhaust(I assume this time at .050" lift). Does this mean that the 'ramp" in the factory cam for the exhaust side is steeper than the intake side? What do you think the intended effect was for this steeper ramp?

The other two (bigger) cams have more lift and more duration for exhaust over intake (at least at the baseline), what is the benefit of this configuration?

I think I have read that at high RPMs the open exhaust valve can create a low pressure zone within the cylinder, helping to draw in the intake charge before the piston starts the down stroke - is that it?

Thanks again,
-Sam