Comments from Royce P on the "other FE Forum, FordFE.com says they are race only, not so good on street. Once i got my pair of stock 1990's 1850s worked out, they are really good now. One set has no choke towers, that's ok in July, but sucks now its January, so i put a choke carb on front for winter driving. Quick Fuels are tunable also, maybe a better option if you want to play with jetting and air emulsions.
here is an external link:
http://www.network54.com/Forum/74182/thread/1203786562/carbs+for+a+2x4+bbl+medium+riser"They are race only carbs that don't have metering blocks. I'll go further and suggest they are probably best for either 500 mile oval track or long distance power boat racing. They are awful on the street unless you replace the primary metering blocks with metering blocks that are capable of accepting power valves.
The BT - BU carbs are actually pretty decent on a 427. They are a little big for some mild engines. Good if you have 500 CI, lots of cam and lots of compression.
The BC - BD carbs were original on the '65 - 67 Medium Riser though and at 652 CFM they are plenty of carb on the street. If you want the OEM carbs that came on a 427 Cobra, these are them.
The BJ / BK carbs are 600CFM and also work great on a Medium Riser. They were original equipment on the late '63 - 64 427 Low Riser. They provide excellent driveability although you probably won't notice any difference from the BC - BD's.
I've tried all of the above carbs on my own stroked 427 (448 CI). In a Cobra kit car you won't have any traction so my recommendation would be either the BC - BD or the BJ / BK carbs.
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