Hey y'all, I've used search and haven't been able to find exactly what I'm looking for. I was hoping someone like me, who has a bone stock 455 (1970 Delta) could tell me precisely which metering rods, jets, and springs they used on their Edelbrock 600 cfm carb. Hoping someone has done this before so I don't have to guess quite so much lol

Thanks for the help!

 

You'll just have to tune it on your car. There are a lot of variables, including where you live. It'll probably run OK out of the box, although 600cfm is pretty small for a 455. But being a Delta I assume you're not winding it up past 5,000 rpm all that often.

 

The original Qjet was 750 CFM. Why handicap the car with a 600? More to the point, for a stock engine, a properly rebuilt original Qjet (7040251) will be the best choice.

 

Can somebody explain what a "bone stock" is? Jargon can be confusing. Perhaps I don't get out enough.

 

but…but….but… the Holley cfm calculator shows a 600cfm is ideal!!!

 

For certain bone stock and edelbrock carb should never be used in a sentence together. I'm figuring Devon means factory correct besides the edelbrock carb...

Devon, edelbrock carburetors are notorious for disappointing consumers. And as has been mentioned 600 cfm is insufficient for optimum performance on a 455. Back in the early 90s when I was having my Cutlass 330 converted to 4bbl, 600 cfm was universally recommended to me. Not by a gizmo that calculated proficiency, but by guys who really knew what they were talking about. 600s are for small block modestly powered engines. And if you've heard otherwise and that it worked out great, the exception does not set the rule.

 

There’s more to carb sizing than just the formula on the Holley website.
AED used to have a great write up on intake tract sizing, in conjunction with carb sizing. I’ll see if I can dig that up.

 

Yep, and yet that’s the go-to when people are carburetor shopping.

if a 600 cfm was ideal, I seriously doubt GM would have spent the money to design the Q-Jet to be 750 or 800cfm capable.