Eldebrock carb big enough for 383 ?

[Racer57]

I have a Eldebrock 1406 600cfm on my HP-383. Is this the proper carb ?

[72cudamaan]

Awfully small for a 383. A 750 would put you real close.

[Sleepychallenger]

I think I have the same and it runs good. Factory was the 625 CFM. I've thought about moving up but when I had the holly 750 on there it fluded bad

[Racer57]

The engine is running hot and has a stumble that can't be predicted when it will happen. Timing is TDC and the radiator appears to be ok. Water pump is stock type, but unsure how many vanes it has. That's why I'm starting to wonder about the carb.

[72cudamaan]

If it's running hot, look further into the cooling system first. Just because the rad "appears" okay doesnt make it so. Does
it always overheat? or just idling or at speed? Are you sure the t stat is opening properly? Are you sure the gauge is even reading properly?
Does the car have the proper fan and shroud?  I cant think of any reason for a properly tuned 750 to flood on a big block.

[Sleepychallenger]

I think mine was an altitude problem. Something about being in Colorado Springs and it adjusting anything on the carb

[cudabob496]

per below, Holley recommends a 600 cfm to 670cfm, if engine is mild race
and does not go above 5500 rpm.


http://holley.com/applications/CarburetorSelector/CarbSelection.asp

[Racer57]

Thanks for the responses. I'm glad to hear the 600 isn't too small like I had thought. I'll pull the radiator and pump and check them out. I was told by the previous owner that everything was ok, but it has set for awhile so maybe some crud broke loose and has the radiator partially plugged.  The stumble still has me confused though.

[Chryco Psycho]

you need to advance the timing , you need about 12* at idle & 36* total . second the carb will work barely ,I would use a 750 Proform as my first choice

[cudabob496]

I think mine was an altitude problem. Something about being in Colorado Springs and it adjusting anything on the carb

Ya, and pot is legal there too! That may affect it!

[Chryco Psycho]

Nice response Bob
 Altitude does affect carbs

[Racer57]

EVERYTHING works perfect now and I feel like a total idiot. Please keep in mind that its been 30+ years since I messed with carbs and timing. Converting points to electronic doesn't work like I had assumed it did. First off, I had noticed that the timing was at the bottom of the indicator plate on engine and I had moved it up thinking I was advancing it. Wrong. Then I had noticed that the vacuum line from the distributor was not hooked up and since the vacuum plugs were in place on the carb and it had been converted to electronic, then the vacuum advance on the distributor wasn't needed. Wrong. After doing some checking and having a good friend that still drag races came by and helped me, the timing is at 8-10 degrees, vacuum line is hooked up and I set the air speed jets better and the car now runs very smooth with no stumbles and doesn't overheat !!!

ALL of your responses helped me think along lines that I wouldn't have and helped tremendously. Thank you ALL !! 

[Chryco Psycho]

Glad it helped 
 I would stil leave the vacuum advance line off & add more timing bringing it up to 12-16* at idle , it should run better yet , retarded timing will always cause it to over heat , make sure the vacuum advance line is on ported vacuum opposite of manifold vac low & idle & higher with RPM  if you contiue to use vac advance