Originally Posted by rich weyand
Get a Comp Cams 12-300-4, 12-235-2, or 12-230-2.
This forum won't let me post a pointer to another forum, so Ima gonna copy and paste a couple paragraphs or ten.
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A word on cams for you.
12-230-2 will work fine. With dual-plane and long-tube headers, 290hp/420lbft. Lift is .432/.444. RPM range is 600-4600.
12-235-2 will wind a bit tighter. With dual-plane and long-tube headers, 290hp/415lbft. Lift is .421/.451. RPM range is 1000-5200.
12-300-4 is what I am running. With dual-plane and long-tube headers, 275hp/420lbft. Lift is .390/.390. RPM range is 600-4600.
So all of these are in the same ball park. 12-230-2 has the same hp and torque as the 12-235-2, but will run out of pull at 4600 rpm. 12-235-2 will match that, and pull to 5200, which is a better fit with stock shift points. 12-300-4 gives up some hp on top, matches the torque in the bottom, but keeps the stock .390/.390 lift, which is easier on the valve train (and cam lobes). That's why I picked the 12-300-4, for engine lifetime sake, since they are so similar in performance.
All three cams will work with stock lifters and springs. Note: NEW stock lifters and springs.
For the 12-230-2 and 12-300-4, you should replace one weight in the TH350 governor with the next bigger weight to bring the stock shift points down 500 RPM. If it's a stick (sorry, I don't remember and it's a lot of posts back!), then you will time the shifts yourself, so no worries.
The cam that's in there is an old cam design. In an ideal world, valves would be open or shut, with no in-between. That would maximize flow while giving you an earlier intake closing for more dynamic compression and a later exhaust opening for longer pressure on the exhaust stroke. Unfortunately, we can't do that -- cams are ramped. You can tell how long the ramps are by subtracting the .050 duration from the advertised duration.
The cam that's in there has ramps in the mid- 70-degree range. All three Comp Cams have modern computer-aided designs with ramps in the mid- 40-degree range. That's 30 degrees less dead space in both the intake and exhaust cycles. The difference that makes in the ability to tune the other cam parameters cannot be overstated.
I think you will be very happy with whichever of those three cams you pick. Not a bad choice among them, really.
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Subtract the .050 duration from the advertised duration for that Summit cam. It has 74 degrees of ramps, so it's an old grind. Not necessarily a "bad" cam, but just much less capable than a modern design.
A note about lope. Everybody thinks they want it, but what it means is that the engine doesn't want to run at 700 rpm. So how much torque do you think you're going to get at 1000, or 1500? An engine that's going to generate torque at low rpm is going to LIKE running at low rpm, so it will idle really smooth.
The way they get launches at the drag strips out of engines with a lot of lope is to run high-rpm lockup torque converters so they can wind the engine up to where the hp is. High-rpm torque converters are great for the drags, but a PITA to drive around on the street, and they're hard on transmissions.
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