I’m running a 283 , presumably rebuilt. I have no access to the history of the engine. I certain, by the running characteristics, that the cam is non-stock.
The carburetor is an Edelbrock 1405 , 4bbl , 600 cfm.
Manifold is Edelbrock dual plane Performer.
Vacuum is 13” , well below optimum. (All vacuum lines , brake booster etc. are new and intact) I attribute the low vacuum to the camshaft. Engine performance is excellent in acceleration or cruising. The only fault is that it’s twitchy at idle speed; frequently quits abruptly when shifting neutral to gear. I do have a new 2500 rpm torque converter; the reduced the problem but did not eliminate it. (that converter sure did improve low end acceleration…)
I’m thinking that there is a relationship between the low vacuum and the unreliability at idle rpm.
My reading suggests that the normal max cfm for a 283 is 480 - 500. My carb is 600 cfm. Is it possible that I would benefit from a 500 cfm carburetor? To put the question in other words: would a 500 cfm carb “cope” with the low vacuum better than the one I’m currently running?
My horticulture degree did not prepare me very well in this area.
Standing by,
CK
