[johnreeves]

Hi All,

I'm looking to change the camshaft in my 1969 firebird, Rebuilt 455 8.9:1, stock rods, 5 C heads ,4 tube headers,350 trans ,2000 stall, HEI, cast intake 750 VS. Camshaft that is currently in the engine is a 217/221 272/278 .454/.454 106. This was my choice with a 2.56 ratio. I had the rear end rebuilt and switched to 3.55 gears and thought there would be a better cam selection to go with since the gear change. After getting some advice I think I will go with a Crower grind. Is there a difference between the 60919 and 60242? I was thinking on going with the 60242 because of the avd.dur being larger. Any guidance or recommendations would be appreciated.

[OINK 1]

With the 3:55's , good choice by the way. Get an Ultra-Dyne 280/288H12+6, degree in@ 103/104. Duration@ .050- 223/231, lift w/1.5 rockers, 463/485. it will rock AND dynamic compression will be around 9.4 to 1 ! Asymetrical ground cams! The Best ! You may call me if you wish and I'll order it for you and the correct lifters.

Pontiac Gregg
1-303-776-0877
Visa, M/C

[gtofreek]

Agree on the UD cam also. Harold's cams are the best in my opinion!

[vidguy]

How would a taller gear like a 2.70 / 2.90 range work with that same powertrain?
What cam changes would be recommended all else the same?

[Thumpin455_GTO]

Originally Posted by vidguy

How would a taller gear like a 2.70 / 2.90 range work with that same powertrain?
What cam changes would be recommended all else the same?

The 70 GTO in my sig ran 13.5@105 with the UD cam Greg is talking about, with 2.93 gears, with a 1900 stall. It would probably do better if I could get the 60 ft under 2.05, the nose on the 70 is stupid heavy so it would spin rather than hook. Havent had a chance to run it with the 3.42 gears, but it sure pulls hard and still wont hook.

The next two mild 455s I build will get UD cams, but since they have 11.3:1 and 12.8:1 they will get 288/296 cams instead. Yeah I believe in the UD cams.

[johnreeves]

Thanks for all the advice , this site is very helpfull. I did have another question for you OINK 1, On the Ultradyne cam 280/288H 12+6 you said to degree to 103/104 . Can this be ground into the cam specs if it was requested? I was planning on installing the cam stright up I don't have any degreeing tools and haven't attempted to do that before. I have aways installed cams stright up with the dots in alignment. I still have some time to think about a selection and try to come up with the best choice. It has got cold in Indiana now. Thanks once again for everyones suggestions.

[screamingchief]

Personally,based on my experience with UD cams in the past,they are the single worst brand of cams as far as being ground "off" is concerned.

No way would I install one that was'nt gonna get degreed.

I've had like three or four UD flat hydraulics and a couple UD flat solids and all were ground off somewhat.

A couple of the hydraulic flats wound up @ like 98° ICL when installed "dot to dot".

Damn good cams after you degree them though,no doubt about that.

And it was'nt the chain set or such either,all other areas of potential error were checked and rechecked to prove where the problem was,it was clearly the cams fault.

Now all those UD cams were from the UD days back before bullet and Lunati took over the UD masters,so I'll concede that the current crop of UD cams may infact be better in that respect,but I personally still would'nt take that chance,especially seeing as I have the gear to check them.

Just my .

FWIW.

[grandville455]

My bullet 288 cam would work well for you with rhoads lifters .. ran it in my 455 !

[Skip Fix]

SC out of the 4 or 5 UD I have degreed all have been within 2 degrees of "correct". Recently after degreeing the cam in the 500" with a cast crank, then a billet there was 2 degrees difference in the cranks not the cam using the same chain/gear set.

[screamingchief]

Like I said above Skip,those were all the old/original UD grinds,I even went on to state that the new crop of UD grinds from bullet or Lunati may indeed be better in that respect.

I agree the flat solids I did were'nt off by much,2° maybe 4° at most.

But the 3 or 4 280/288 & 288/296 hydraulics I did were waaayyy off.

As they say,,,once bitten,,,well we all know the rest...

I did say they were good cams after degreeing,,,did'nt I???

Truth be told,those UD hydraulic cams were pretty much the main reason why I own a my own cam degree kit now.

Which is a good thing IMHO.

I did'nt have my own kit back then,used to really hate constantly borrowing my friends kit to install another cam.

[Skip Fix]

These were all from UD in the nice purple box! But you are right EVERY cam should be degreed.

[Malky]

johnreeves, you definitely want flat tappet? A lot of people on here, including me, switched to hydraulic roller because of some break-in disasters with flat tappet cams. Expensive cam set but so is rebuilding the engine.

[gtofreek]

SC, I once degreed a Chet Herbert cam and it was so far off, I had to retard it 6 degrees, in order to advance it 4 degrees!?