Holley Help Needed

Ok so the Edlebrock streetperformer single plan is out.....I have a new Edlebrock performer dual plan here is that any good for what I want to do ???

Again I only have the 600 Vac Holley for now but will upgrade soon I was thinking that I would start with changing the 63 jet to 67 & see if that helps yesterdays test run the car seemed to lack top end just wouldn't rev up quickly...

Also what timing would you recommend I setit at 10 BTDC at the moment & it seems to start & run fine no run on or pinging.

Cheers Graham.

Graham, Lets iron out a thing or two here. The lingo between oceans is going to get things mixed up.

What is the exact name of this single plane "Edelbrock street performer" you have now?

What is the exact name of the dual plane intake manifold you have.

The lack of a quick rev can be a multi issue problem. We'll get to that in a min. Lets just get things squared away first. A 600 cfm carb is not an end all item.
Well get to timing in a second as well.