I recently bought a stock rebuild 400 Chevy short block that came with the cam. The previous owner had 305 heads on it with a 600cfm Holley with this cam I got with it. The motor was in his competition pulling tractor. Anyways, I'm going to be using 062 350 Vortec heads with this 400sbc. I already know I have to have the steam ports drilled in the heads. But is this cam to much for these heads?? The specs can be found here:

http://www.cranecams.com/product/car...detail&p=23895

I'm a noobsickle when it comes to understanding cams and what all the different specs mean and stand for.

 

That's the "1st design off-road" cam, a REALLY OLD design; quite good in its day, but that day was about 40 years ago.

It was around 248/254° @ .050" if memory serves; right close to .500 lift, like about .495"/.510" or thereabouts; and tight lobe separation, like 108° or maybe 106°. ALOT of duration for VERY LITTLE lift, by modern standards, and a VERY peaky torque curve. One of those cams that's designed to run in a HIGH narrow RPM range. A good characteristic for a close-ratio racing setup, not so good for a street setup.

A 600 carb is COMPLETELY inadequate for an engine designed to run in the RPM range supported by that cam. Basically the whole thing you've got there is a giant mismatch.

Look at a Comp XE274 or a Lunati 60103 I think it is (the one that's about 227° on the intake, whichever # that is). A 750 carb would be about right.

The steam ports are a little bit of nothing; hardly worth more than a moment's thought. You can put them in by yourself. Takes less than 5 minutes a head, if you're slow like me, and you stop for an entire cold one in between each pair of holes besides; you can do it MUCH faster I'm sure. Just lay a 400 head gasket on the heads, center-punch where the holes go, and drill with a 3/16" bit. Angle the ones on the int side about 15 - 20° toward the exh ports, away from the head bolt that's right next to them, otherwise they often hit the place in the casting where that head bolt goes through it. Here's a set of heads I drilled em in.

 

Thanks for the info, the last owner ran that cam in this block with 305 heads and a 650 Holley on his pulling tractor. I figured that cam was all wrong, but wanted a better explanation as to why.

 

Those specs wouldn't be half bad in a hydraulic roller with faster ramps and less .006 duration. But in a solid flat tappet it would be a bear on the street and alot of time spent adjusting valves.