First off its a modded 355 SB motor. Its got Edelbrock RPM heads,Air gap intake, comp cams,forgot spec. 1.6 roller rockers. Complete MSD system.750 Barry Grant carb.Hedmanheaders to single 3 inch Flowmaster muffler.
The car seems to be running rich and we cant come up with an answer. Is the carb too big? SHould he get a 650? Any info... it idles fine.

 

thanx for the help i new this place was worthless.

 

I'm willing to bet that the 750 is calibrated from the factory for a bigger motor. This doesn't mean you can't use it, it's just they install larger jets, and rods by default.
I know the Edelbrock's come this way from the factory. Most guys who get the 750 over the 600 find they need to jet it jet down big time.

Here's an example right from the Edelbrock manual.
Stock(default) Calibration:

600CFM(1405) Jet = .100 / RODS = 070x047
750CFM(1407) Jet = .113 / RODS = 071x047

BTW: I dropped a Edelbrock 750 on my 350, and I live at 6300feet. It idled fine also, but flames where coming from my exhaust. My plugs foulded in short order. I leaned it out about 12%, and I'm close to optimium, but still need a few more tweaks.


Ron

 

thank u roterry thats all i needed to know.:hail:

 

You make that complaint quite often :nono:

If such is the case why do you ever bother posting here at thirdgen?

Please display the same respect for the members here as you desire for yourself. Sometimes it just takes a little while to get an answer. It is the same for all of us