Holley 650 cfm marine quadrajet replacement carb
 

Anybody use one on the street, will it work out of the box or does it need re-jetting?

I've used plenty of spread bore's outta the box. They'll work just fine on stock motors, with a little tweekin'. Not sure what's special about "marine". Any mod's in the motor and it'll be "tune to fit".

I read on holleys site that marine carbs are tuned for constant load, automotive carbs are tuned for variable loads. Dont know if that makes much difference?

OUCH, fraid it might be something like that. Metering blocks and power valve differences. Make it "stumbble" off the line. Might run fine wide open, if it were race only.

thats what im thinking too :?