I have a 454 in my 1970 Chevelle. I will be switching to the new Tremec 5 speed and may swap the cam while I have the engine out. My current specs are:
9.8 Cr
Forged pistons
Crane Hyd 296/306 cam
236/246 @ .050
114 LSA
Edelbrock Alum heads "roval" ports
165 cranking psi.
3.55 gears w/posi
2600 stall - will change to a manual trans.

My current combination runs good, idles at 850rpm, will quickly scream to 6300. However, from what I've read here a solid flat tappet cam would provide a general improvement. The only consideration I unfortuantely need to make is I have to pass the 4 minute federal emission test. I can currently pass by using a leaned out 750 Holley and reduced ignition timing. I pass the idle test at about half the HC and Co standards and the cruise test it passes easily. Can someone provide a solid cam recommendation that will work well with a 5 speed, pull to 62-6400 and still meet the emission standards TIA

A UD276/284 or 280/288 is a close match to your old cam. Lunati Cams (http://www.holley.com/HiOctn/ProdLine/Products/IEC/IECC/Chevy7.html)
The 114LSA is probably why you pass now. You should pass with the 276 @ 110 using the same tune. The 280/288 might need more tuning or a 112-114 LSA.
I passed the old test in CA with a 288/288 @110 Erson
850dp and a 450ppm HC limit. Barely.
I think you could tune the 280/288 to pass but I can't say for sure. Looking at your DCR, I'd use the 276/284F10.

I was actually thinking of the next step up, 280/288. I think it is close to the comp 294S. Maybe Harold could jump in here. If I do this I want him to weigh in too.

Wow!!!; they still smog 70 chevelles out there. Here in california they are smog exempt after 30 years.

Actually, although the CC 294S and my 280F look very similar---CC 294S, 248 @ .050, .595 valve lift, UD/LUN 280F, 247 @ .050, .595 valve lift,--- at .200" the UD/LUN is 5° fatter than the CC 294S. The UD/LUN 288F is 12° fatter at .200.
My personal opinion? The 280/288F will out-power the CC 294S across the board.....
Just simple physics....

UDHarold

I can tell you that the 276/284 is the best cam I have run. And I have tried many. Including Comps. new extreme series. I would not have a clue about passing emissions though. I would think if you leaned and retard anything enuff it might pass. My setup is as follows:

454 std bore
Speed pro hypers 100 dome
UD 276/284 solid
Closed chamber recs.
RPM airgap
750 dp Carb shop
Hooker 2" hedders
3" flowmasters
All MSD ignition and dist.
2800 stall converter
Manual valve body Turbo 400
307 gears

This thing is a smile machine :D .

Bret,
A few questions.
what is the idle speed, vacuum reading, cranking psi?
what rpm does it seem to pull to?
how rough/lopey would you consider the idle?
Thanks.

I have about 14" at idle out of gear and about 12" in gear. I idle at 850 in gear and it is a very healthy idle. Not to much to handle though. (I had a 284 extreme energy before this and it idled ruff) Before I put the 6000 chip in, it would pull very hard and fast to 7000+. My bottom end was not built for 7000 to many times so I stick with 6000 even though it wants more. Lash is .026 on both cold.
Can't tell you the cranking pressure. If you really want it, I can hunt down the friend who has my compression tester and get a reading for you. I think you would be happy with this cam. I have about 3000 miles on it and drive it most everyday.
Bret.

Thanks but I won't ask you to test it. If you ever make it up to Phoenix for a car show, swap meet, etc and you bring the Elky let me know.

What grade fuel do you use?

Getting your cranking compression to 185-190 psi would really shake things up a bit!( if the engine didn't get too warm). It would certainly bring the torque up. Other than emissions, I think you'd much more enjoy a tighter lobe separation as well.

I will do that. I am disapointed that Super Chevy is not coming to AZ this year. Maybe Goodguys in Scottsdale. That is if I ever finish the body and paint.

Originally posted by Live466:
I can tell you that the 276/284 is the best cam I have run. And I have tried many. Including Comps. new extreme series. I would not have a clue about passing emissions though. I would think if you leaned and retard anything enuff it might pass. My setup is as follows:

454 std bore
Speed pro hypers 100 dome
UD 276/284 solid
Closed chamber recs.
RPM airgap
750 dp Carb shop
Hooker 2" hedders
3" flowmasters
All MSD ignition and dist.
2800 stall converter
Manual valve body Turbo 400
307 gears

This thing is a smile machine :D . What kind of ET's do you get with that combo?

Thanks!!