383 cid
about 10:1
500 lift full roller 245@.050
vortec heads (2.00int, 1.55ext)
super victor single plane.

this combination on my desktop dyno yeilds about 480lbft at 5k and 510hp at 6k

the carb calculators i have been searching on say a 670cfm will work for me.

anyone else running a similar setup? seems a little small for my setup. was originally looking for a 750dp

 

Tell us more about your car. What gears, tranny, intended use? The cam and intake say drag race. If thats it then a good ol' 750 DP. I have a Proform on my stroker. Couldn't beat the price at the time. Now there are a couple others in the same price range. I wanna say mine was about 500-550. I really can't remember.

If your building a fast street car with an automatic trans. A 750 vac secondary would be a better choice.

Would you be interested in plugging my combo into DD. I don't think its really close but just for fun I'd like to see what it says. I have head flow data and camshaft timing to input. Please! Oh yeah welcome.

 

Your 510 h.p. estimate may be a bit high. In some instances, our engines are more similar than not. Mine has slightly more c.r., our cams are almost the same, my heads are older style, but well worked over. When I ran DD on my engine, I came up with 454 h.p./488 tq. With the AFR heads I would like to get, 514 h.p., 523 tq. I don't think my jump up is going to be quite that much, since I doubt DD can take into account all the stuff that's been done to the heads. That, or my 454 h.p. calculation is low because of how my heads are now. Yes, you have Vortec heads, but I wouldn't put them up against the AFR's. I wonder if you entered all the info correctly? But to answer your main question, a 750 cfm carb.

 

DD is a nice aid to guestimating HP, but from what I've seen it's almost always quite high. I've had a couple friends who ran DD on their engines, and then dyno tested them, and in both cases the engines were around 40-50 hp less than DD came up with.
As Camaro 69 said, there are variables that DD doesn't take into consideration.

 

sure, gimme some specs. i love playing with this thing,

and although it may not be HP accurate, it should be fairly accurate at which combo's make more power than others.

here's what i got plugged in for mine,

looks like its closer to 500hp. i think its about 506 if i remember right

 

I agree, I only use DD out of curiosity, to see what type of changes different components will make. Take the numbers with a grain of salt.
One thing I missed, you're running a roller cam, mine is flat tappet.
And, are you using large tube (1-3/4") headers? Change those DD specs if you're not.

 

i don't have the headers yet. but the header calculator i used called for 1 3/4 x 37.5 primary tubes.

so i'll look for some 1 3/4 by 30's maybe, summit has a lot of those available.

or maybe screw the length, schoenfeld has a lot of good 1 3/4 headers available for fairly cheap.


oh yeah...

i'm running 4/10's
auto trans, with shift kit and 2k stall speed

 

Did you, out of curiosity, run the numbers on smaller primary headers? Those may give you a lower rpm torque curve (you're peaking past 6 grand now), which is more street friendly. Not to mention the possibility of having less clearance issues. I put these headers on my car, and it appears to like them. Sounds like a good concept, but I didn't have the means to do an "old to new" field test. Flowtech 49100-1FLT - Flowtech Afterburner Headers - Overview - SummitRacing.com

 

Any one thing I change doesn't really affect the power that much side from head size and porting or not,

how big are those headers?

 

Most of my experience with carbs comes from a few years back, but one thing I learned was a lot of motors are over carburated. I have always run AFB's so my choice of carbs now will be Edelbrock. I think you are close with the 670 you came up with.I'm looking at building a mild 350 and am going to run a 500cfm.