I am running 10.7:1 compression with the saturday night special cam which has an advertised duration of 280/288, gross lift of 5.18/5.36 before the 1.6 rockers, duration at .050 is 244/252.
Grind Number: F-244/3454-2S-6

I was wondering what kind of gas i will need to run with this and how much this affects my compression ratio. Also what kind of idle can expect.

So many ask questions like this, that I linked Pat Kelleys DCR calculator into the electrical sticky's!

Look here:
http://www.camaros.net/forums/showthread.php?t=71062

In addition to the downloadable calculator, there is an excellent writeup on this.

ok hold on. I Need help with this configuration. I just did it and i got a 8.49 DCR.

Ok so here it is. The ICA is 66*. THe engine is a 383 so a 3.75 stroke and a 4.030 bore. It has 5.7 rods and a 64cc combustion chamber. The compressed head gasket is a .04 i believe and i dont know the Piston to deck clearance or the cc's on the pistons but i used some information to figure the Piston to deck clearance is about .017 and the piston has a negative volume of -5cc maybe those numbers are wrong and can change the calculations alot but i don't know. THe SCR is 10.7 i know that for sure.

What heads are you using? With modern style fast burn type heads, and a tight quench, you *might* just squeek by on pump gas.

Idle quality will be pretty lumpy...that cam is on a 106 lsa. It probably won't work with power brakes, if thats an issue for you.

Take Pat K's DCR calculator and work backwards by plugging in intake valve closing events until you come down to like 8.1 to .2 or so...

And I figure something around your cam, but on a 114 LCA should put you in the ball park, not running it through a DCR program. You will increase the closing point to bleed off a bunch of compression doing this..

Heck, I bet the old 30-30 solid cam will get you there too!!!!!!

What do you say, Travis???

pdq67

They are old 462 heads now with like 2 grand in the springs, large valves cut, porting and polishing done too. I am eventually putting AFR 210's on it. We will see if it will work. I am thinking thats pretty high though maybe buy some tetral of lead or maybe buy race fuel and mix it. I would really like to be able to run on 93

On my cam card it says makx intake lift at the cam timing of .050 tappet is at 102 degrees thats not the intake centerline is it?

Yes, its the intake centerline. The cam has a 106 lsa, and a 102 ica, meaning its ground 4* advanced from the factory.
I think your going to run into detonation issues with that setup and pump gas, but the only way to know for sure is to try it. I'd bet your going to have to throw a little race gas to the mix, but it should run hard.

Man its an 8.75 now with the 102 ICL. I wont run into detonation when breaking the engine in will i? Crane says it should run on pump gas with 10.5:1 compression but with 10.5 to one even its like 8.6 dynamic

It most likely won't have any issues breaking in the cam and stuff on pump gas, because you won't be driving it, and you won't be hammering it (I'm assuming ;) ). I would still use the best pump gas you can get and maybe throw in a little octane booster to be safe.
What gearing and tranny/convertor are you using? Another option for you may be as simple as a different cam.

3.90's and a turbo350 the converter should be around 3,000. i am going to get one sepicifically for my set up. I am not going to change it around

You want to actually check your deck ht, too.

I expected around a .020" deck when I did my 383, numbers matching block never decked. She came in at ZERO deck!!

Guess those chinese rods are a schosh long?

I think the cam I am running would be about perfect for your setup. I am using a comp cams 294s solid flat tappet. It is on a 110 lsa. In my 10.3-1 388, it cranks 185psi and runs easily on pump gas. It would probably run fine on 87 octane if I tweaked the advance curve a bit more. And it still sounds plenty nasty, and is very driveable with a strong, wide powerband.
Just something to think about.

Heck, I bet your cam will run just fine installed straight up at 106/106!!

And you won't lose all that much on the low end what low end you will have.

As always, jmho..

pdq67

To run the cam straight up all i have to do is move it 4 degrees because the ICL is just where the cam manufacture specifies is straight up right??

Yes, retard it back four degree's from 106/102 to 106/106.

And I bet you could even go back farther to 106/110 to allow the intake valve to close 8 degrees later and thus bleed off more cylinder pressure.

There is theory about doing this so that you create max. blow-down on the piston before opening the exhaust valve

I looked at a little bitty solid lifter cam for a 9.5 to 1 CR., 283 that was like 250/210, 104/108, .450 gross lift and it created onna the flattest torque curves I'd ever seen off idle until like 4500 rpm with just a dual plane intake and small headers.. Very interestiion to me, but I don't have any rreal world experience with this stuff, only D2k's sim's is all....

And I will say that I have read somewhere in an old article about roundy-rounders buying a lot of cams like yours that aren't talking about just where they dial in the intake valve closing point.....

I hope other, more knowledgable guys will chime in here to offer more help and real world experience for all of us to learn from....

pdq67