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shelby987 · 12-04-2005, 11:23 AM

I have a 250 I will be installing on my truck in the near future, the PO built the heck outta this thing, to the point where he felt a 7,000 rpm limit was very feasible......he planned on running a 650cfm 4 bbl on the engine. I am looking for a d.d. with power, but respectible mpg. I was looking for a 390 or 500 cfm ferd 2bbl, but came across a 390 4bbl instead.....would I be looking at similar performance/mpg setup with a 4bbl instead of a 2bbl or am I missing something?
I guess it boils down to this....whats the difference between a 4bbl 390 and a 2bbl 390cfm carb????

12-04-2005, 11:23 AM	#1
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	4bbl on a 250? I have a 250 I will be installing on my truck in the near future, the PO built the heck outta this thing, to the point where he felt a 7,000 rpm limit was very feasible......he planned on running a 650cfm 4 bbl on the engine. I am looking for a d.d. with power, but respectible mpg. I was looking for a 390 or 500 cfm ferd 2bbl, but came across a 390 4bbl instead.....would I be looking at similar performance/mpg setup with a 4bbl instead of a 2bbl or am I missing something? I guess it boils down to this....whats the difference between a 4bbl 390 and a 2bbl 390cfm carb???? __________________ 1969 SS 350 Camaro Sold 2008 1970 3/4T K20, stock height with 33's, 250 I6, 3 on the tree, and locked front and rear 4.10's 1980 Chevy Malibu 2 dr Sold 2007 1993 Olds. Cutlass Ciera Wagon Traded 2006 2003 Saturn L200 w/5pd. D/D My list spans 5 decades with One common thread.....GM!