Even with your gearing I would lean towards the bigger of the two-it would be a strong runner

 

what cam does it have now?

 

To me it screams 60104, but I like a little more cam than most, if it's not going to see any track time and just cruiser, I would put the 60103 in there. That will be plenty of cam to sound good and will still run very strong!

The 60103 will have better street manners overall.

-Bobby-

 

i drive my velle as much as i can.
355 with voodoo hyd roller 60122, 231/239 535/550 brodix ik180 heads.
it drives very nice! almost no surge, low vac, but sounds good, and pulls great
just some food for thought

aaron

 

This is a new motor.It has a stock 350/300hp in it now.Its going in my 70 corvette i may bring it to the track to see what it will run.

 

I am very interested with this question since I'm searching the same exact info... 60103 or 60104... I have a 66 chevelle with a 383, 4spd manual and a low rear diff. (3.34-3.55 or something).

I want some better vaccuum than my current cam gives (10 to 8 mmHg) and a more midrange power curve. It's my summer daily driver and sees some drag days. I also like to push it hard... pedal to the metal is my driving style

The 60103 is rated 1800-6200 but on a 383, that rpm efficiency range may shift down, making the 60104 probably more interesting since i'm not building a towing rig

 

I'm running a 383 with Perfomer RPM heads and 10.1:1 compression in my 3450 lb 70 Chevelle (3620 with me in it). I use it for moslty weekend playtime. Once in a while used for the 1hr commute to work. Headers, dual flowmaster exhaust. 3:55 gears and 2200 stall. Nothing too flashy or racey. I drive it like I stole it!

I don't run power brakes. I'm running the Comp XR276HR, but it's a roller and I'm running 1.6 rockers. Effectively, my specs are .226/.232, .535/.544. so a little more lift and slightly less duration than the 60103. 12Hg vacuum at idle (like, I said, more lift) Same LSA/ICL.

I've recently been enlightened as to the importance of dynamic compression ratio (DCR). I plugged in my 383 specs, which should be similar to yours, into this calculator:

http://kb-silvolite.com/calc.php?action=comp

I get 10.16:1 static compression and 9.4 Dynamic (Yikes!) That's high. That cam closes the intake really early. I've read that ideal on the street is about 8.25. It's also a lot of engine theory, somewhat debated if aluminum heads will allow for more, and it's based on really weird math, so it's not a set in stone number.

I'm no expert on that subject, so hopefully someone will weigh in with their experience.

The larger cam will bring your DCR down to 9.3. Can this be right?

Mine is at 8.2 which is (arguably) close to optimal as configured with the XR276HR (Intake closing at 64 ABDC)

I agree that the 383 can take quite a bit more cam, but:

1. I LOVE how this cam sounds.
2. It has really good street manners.
3. That combination makes for one VERY fun street car! Torque all over the place and it pulls all the way through 6000 rpm, which is about where my sphincter begins to tigthen. I'm a little gunshy about over-revving the motor. That's why I went 383. I don't have to rev it high to get that beast pulling hard. I have no desire to do 200 mph, but I do like to mess with the import punks on the street light to light : )

Traction? Fughedaboudit. Smoke 'em up. Even more so in your Vette!

Maybe get some more opinions about that DCR though. I'd eb very interested to hear what others have to say. I purposely avoided a different set of pistons because it would put me up in the 9.3 DCR range.

 

Given those 2 choices:

No doubt & most definitely the 04!

(Even though I would personally prefer a solid stick for their advantages)

 

I was running the 60105 in my 383. It did make good power and was very streetable and great idle.Ended up changing the cam over the winter to a solid roller. Highly recommened if you can swing it go to a solid.