carb questions

[460Waikiki]

I have a few questins about the carb my 460 used to have...
I know it had a holley 4brl carb it had mechanical primary and
the secondary was plain just the jets and floats in the back.
It was running 76 P and 82 S jets. since the carb is gone now.
I got a hold of a 750 speed demon (double pumper, mechanical)I must use this one its only one i have for now.
I dont know what jets i should use in it. I know the engine has
after market mods like double roller chain trw dished pistons.030
and performer maonifold, and some smog d3ves,stinger ignition. but i forgot to check the cam for specs while i had it apart .so i dont know were to start on the correct jets sizes. Would this a good carb opposed to the old holley??also how do i select the right size power valve???thanks all info is appreciated.

[LakesOnly]

Start with the same jet sizes and new spark plugs and do a plug reading after some passes. Adjust from there.
LO

[spectras only]

Like LO said ,start with same jets [ I would start with 72's for a 750 cfm carb] running the boat WOT for a few minutes shot the engine off and pull some plugs to check colour. ps; use a 6.5 power valve.

[DaveA]

I have a 750 Speed Demon w/manual secondaries on the bench and just out of the box I got for cheap from a drag racer. It's the 1402010 model w/76&83 jets and a 6.5 power valve. According to the tech guy I spoke with Tuesday, that's the standard setup from the factory. Big issue is cam specs- it's not designed for anything w/ more than 240 degrees on the cam- they say it won't idle well with more duration. If that's what you're trying to do, they say use the Mighty Demon in the same CFM- different internals, base and metering blocks etc.
Demon specialists online (http://cuda66273.proboards23.com/ind...num=1078854489)
You'll find the Barry Grant tech guru and others here.