[68 SS 396]

Hi guys I have a 68 ss 396... Bored .30 over and was curious, I'm getting mixed reports on what carb to go with I currently have a Holley 750 on it with an edelbrock high rise intake...is that too much carb? I've been told by people it's fine, I've also been told its too big and I need to drop to a 650. Please help any advice would be greatly appreciated...keep in mind the motor is basically stock except for being bored over.

 

[mr 4 speed]

750 cfm is just fine for a 396
look at it this way,the factory has used a 585 cfm Holley,a 750 cfm Qjet and a 780 cfm Holley on the solid lifter 396 motors.

 

[mfret1970]

Double pumper or vac secondary? Either way, you won't be hurting anything with a 750 on a 396. I ran a 750dp on a 396 with way too much cam, my buddy used one on a 350 with the Perf RPM cam and it still worked well.

 

[68 SS 396]

Thanks for the advice guys you probably just saved me $400 much appreciated

 

[putput]

If it aint broke, dont fix it. Ran a 750dp on my 396 for 12 years.

 

[Bob's66396]

Shane,I have a 750,3310 vac/sec Holley on my 66 396. Stock cast intake,headers,and a 270 Isky cam. I had the original 600 cfm 3139 Holley on it,and the 750 made all the difference in the world with mine...Bob

 

[bracketchev1221]

Leave it alone. It's not worth the money. You are in a gray area. The carb is a little big, but it is not enough to worry. There are people with 750's on 350's.

 

[vrooom3440]

My experience is with Edelbrocks on a 402 with a bit of cam... idles in neutral with about 11-12" of vacuum.

The 600 is more street friendly as it stalls less coming off idle at stops. The 750 would tend to drop vacuum very quickly and stop pulling fuel from the idle circuit leading to a bog. I have not really been able to tell a power difference in street driving.

I also find that the 600 is much easier and more consistent to tune than the 750 was.

Obviously YMMV :beers:

 

[Ray Gasser]

I run a 780, vac secondary on my mild 496 and it loves it.
Personnaly I would not change for my set up; but don't be afraid to experiment, that is how we learn.
Got some friends with spare carbs sitting around?

 

[osdmike]

Hi guys I have a 68 ss 396... Bored .30 over and was curious, I'm getting mixed reports on what carb to go with I currently have a Holley 750 on it with an edelbrock high rise intake...is that too much carb? I've been told by people it's fine, I've also been told its too big and I need to drop to a 650. Please help any advice would be greatly appreciated...keep in mind the motor is basically stock except for being bored over.[/QUOTE]


Since Your motor is basically stock, I think a dual plane intake manifold would be a better choise.
You can also use this formula for carb size:

cu.in. X max rpm
.......3456............ = ?
------------------------

408 cu.in. X 5500 rpm
...........3456............ = 649 cfm.

------------------------

Or........,check his out !
http://www.holley.com/applications/CarburetorSelector/CarbSelection.asp

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