Looking for carb suggestion for my 383...

[russg]

I've about had with the Holley 670 Street Avenger, I just can't get it tuned right.  It appears to be about 7-8 years old, it came with the car when I bought it and it was terribly out of tune then and even had a rivet in the vac secondary lever forcing a mechanical secondary out of it I guess and wondering what else they may have fiddled with.  To me this 383 motor should just run alot more crisp and have more power.  I've gone through numerous jet sizes, power valves etc..  My late model V6 charger (with headers and some other bolt on stuff) pulls a hell of alot harder than this BB motor and gets 24mpg to boot, mpg is obviously not what I bought the old charger for of course but I should be able to make it faster than a V6 right?

What are some good easy tune carbs to go with from your experiences?  Current setup basic 383 with Eddy rpm intake, headers, full 2 1/2" exhaust, just installed a Dynamic 11" converter which actually helped some.  May have a mild cam in it's future as well.

Just love this site, so much info and help here!

[russg]

Forgot to mention 3.55 gearing but I'm actually thinking about going with a taller gear for better highway driving

[firefighter3931]

Russ, here's a good thread on tuning a 383 with a 670 street avenger carb. Allways start with the ignition first before working on the carb. 

http://1970chargerregistry.com/70messageboard/viewtopic.php?t=1207



Ron

[russg]

Ron,
I found that thread a few months ago and read through it carefully implementing many items as it is more or less the same setup as mine.  While much better it just doesn't feel right and getting frustrating tinkering with the damn thing.  I took a 100 mile drive yesterday and ran good but smells rich like fuel after a long drive and it's getting like 10mpg even cruising.  At part throttle, as in holding just past idle for slow steady acceleration there is like a dead s[pot where it continues to stumble, you have to push the accelerator harder to get past it this dead spot.  Maybe the vac secondaries?  I still don't know if the back bowls are adjusted correctly even when using the sight plugs, when rolling to a stop, you have to wait for the carb to catch up because if you just stab at the pedal right away it can backfire and die, you have to take careful stabs at the pedal and then all is well.

[firefighter3931]

Russ, it sounds like the accelerator pump circuit needs some tweaking.

Make sure the arm is adjusted correctly on the primary accelerator pump.

Are you still using vacuum advance ?


Ron

[71383bee]

What is your timing at and what compression are you running?  

Sounds like my 383 before I rebuilt it...found out it was originally built with 7.8:1 compression.  It was a temperamental bitch!  

You need to be very careful with the 383 because almost all of the replacement pistons are miles in the hole s and result in anemic compression if proper head selection and/or head work is not done.