Which carb for my 347?
Thread Starter
4th Gear Member
Joined: Feb 2006
Posts: 1,001
Which carb for my 347?
I know this subject has been beat to death but just picked up my motor Friday from builder (btw Fordstokers.com has been great to work with) and need to put carb on it. It's a 347 with trick flow heads, edelbrock performer rpm, and comp cam (Duration 274/282, Lift .555/.565). I've got an edelbrock 600 sitting in box from another motor I have but concerned this would be too small. Just curious on what other are running with similiar set up. Thanks in advance.
6th Gear Member
Joined: Aug 2007
Posts: 5,896
From: Elk Grove, CA
Wow, that's a lot of lift...
My 600 Edelbrock is on the small side for my 331 w/Trick Flow heads. It runs great as a daily driver, but it isn't as adjustable as some people might like.
You have a bigger motor with a bigger cam. I'd say 650-700CFM, although I'm sure that 750 QuickFuel would tune out just fine.
My 600 Edelbrock is on the small side for my 331 w/Trick Flow heads. It runs great as a daily driver, but it isn't as adjustable as some people might like.
You have a bigger motor with a bigger cam. I'd say 650-700CFM, although I'm sure that 750 QuickFuel would tune out just fine.
Thread Starter
4th Gear Member
Joined: Feb 2006
Posts: 1,001
Here are the exact CAM specs
Cam Style Hydraulic roller tappet
Basic Operating RPM Range 2,200-6,200
Intake Duration at 050 inch Lift 224
Exhaust Duration at 050 inch Lift 232
Duration at 050 inch Lift 224 int./232 exh.
Advertised Intake Duration 274
Advertised Exhaust Duration 282
Advertised Duration 274 int./282 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.555 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.565 in.
Valve Lift with Factory Rocker Arm Ratio 0.555 int./0.565 exh. lift
Lobe Separation (degrees) 112
Intake Valve Lash 0.000 in.
Exhaust Valve Lash 0.000 in.
Computer-Controlled Compatible Yes
Grind Number FW XE274HR-12
Cam Style Hydraulic roller tappet
Basic Operating RPM Range 2,200-6,200
Intake Duration at 050 inch Lift 224
Exhaust Duration at 050 inch Lift 232
Duration at 050 inch Lift 224 int./232 exh.
Advertised Intake Duration 274
Advertised Exhaust Duration 282
Advertised Duration 274 int./282 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.555 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.565 in.
Valve Lift with Factory Rocker Arm Ratio 0.555 int./0.565 exh. lift
Lobe Separation (degrees) 112
Intake Valve Lash 0.000 in.
Exhaust Valve Lash 0.000 in.
Computer-Controlled Compatible Yes
Grind Number FW XE274HR-12
6th Gear Member
Joined: Apr 2007
Posts: 10,468
From: California
That's actually a somewhat moderate cam for a street performance 347, it'll make a crapload of torque, especially midrange. It's not all that big for a 347 in a Mustang. But yeah, a decent 347 like that really does need a 750.
To give you an idea on the Quick Fuel sensitivity, when I put the 650 mechanical with annular boosters on my 302...it was so stupid sensitive out of the box, that I could have gone with the 750 annular and been fine. I ended up having to jet down like 6 sizes and increase high speed air bleeds by like 4-5 sizes to reduce the booster sensitivity. They make a VERY responsive carburetor, so you can get away with running on the big side and still be fine at low rpm. You just have to not be afraid to learn to REALLY tune a carb.
To give you an idea on the Quick Fuel sensitivity, when I put the 650 mechanical with annular boosters on my 302...it was so stupid sensitive out of the box, that I could have gone with the 750 annular and been fine. I ended up having to jet down like 6 sizes and increase high speed air bleeds by like 4-5 sizes to reduce the booster sensitivity. They make a VERY responsive carburetor, so you can get away with running on the big side and still be fine at low rpm. You just have to not be afraid to learn to REALLY tune a carb.
