Edelbrock 1405 ( 600 cfm) on a 273

[txas2step]

Anybody running a 600 cfm Edelbrock on a stock 273. Wondering if it might be too much. I have a 500 cfm on my '65 dart gt hp 273. Thanks, Chris.

 

[toolmanmike]

I have a 600 on mine. perfect!

 

[toolmanmike]

The secondary butterfly's are larger than the holes in the intake though.

 

[rumblefish360]

A thick gasket should take care of that or bore the intake

 

[toolmanmike]

A thick gasket should take care of that or bore the intake

Agreed. I machined the intake when I had it off.

 

[pishta]

600CFM is max, the 273 wont ever pull that. Your good. you could even get a way with a 390 Holley, but the 60's Buick Carters were pretty small too, like 450CFM.

 

[toolmanmike]

600CFM is max, the 273 wont ever pull that. Your good. you could even get a way with a 390 Holley, but the 60's Buick Carters were pretty small too, like 450CFM.

The stock carb was around 500 cfm . I installed a 600 to diagnose a rough idle issue and never changed back. I still get close to 20 mpg on a highway drive and I haven't had to change plugs for years. (Around 10,000 miles.) Someday I would like to tune the 600. It was straight out of the box.

 

[clifftt]

I have the 500 on my 273 with Egge high compression pistons. It had a light hesitation with a 1403 installed out of the box. I enrichened it with the Edelbrock timing kit, runs better. It's a new engine, though, I haven't revved it much past 4K yet. It might need a little more gas.

 

[pishta]

Get a $150 wideband meter. you can instantly tell wha the carb is (not) doing and will direct you to a solution. On a Carter its a completely different principle of operation than a Holley when it comes to metering but you should nail your issue. The 600 as all carters/Rochesters were velocity sensing so they were very forgiving on mismatched CFM's. Holley DP's were opposite, open those toilet bowls mechanically and its go time whether the motor was ready or not.