carb choice for a 455

[AndersonRacing44]

im building a pontiac 455, 118cc heads, with TRW high compression pistons should be around 10-10.5:1
crower cam intake 311 at 5.12lift
exhaust 316? at 5.24 lift? cant remember the exact numbers.

now its a OEM 4bbl intake trying to find a edelbrock for cheap.

the carbs ive got that would work are a Q-jet from a 454 BBC or a 850 spread bore holley double pumper.

which would work better for me?

 

[melsg5]

You didnt mention automatic or manual or what rearend gears. An automatic with a stock stall convertor and a low numerical gear ratio may not like the double pumper. The quadrajet is more forgiving.

 

[AndersonRacing44]

sorry it has a close ratio 4-speed M-22 and im going to put around a 3.23 rear gear in it.

 

[melsg5]

I'm not sure the double pumper would be the right choice for that ratio, what is the list number on the holley, it's located on the front of the air horn?

______________________________

 

[bustd knuckles]

Carb

If it were me I'd use the Q-jet. The 850 would be like flushing a toilet. The only way I coukd see using the larger holley is if you have a 4 speed or a 3500 or bigger stall converter. Bigger isn't always better

 

[AndersonRacing44]

yea thats what i was thinking, in general thats true for smaller motors, but since this is a 455 thats going to be pretty strong i was just thinking about it. and the Q-jet came from a 454 BBC.

 

[melsg5]

whats the projected maximum RPM of your engine?

 

[AndersonRacing44]

I dont plan on running it over 5000rpm but im estimating 5500-5800 it will do safely but by then the power/torque curve would be long gone.

______________________________

 

[melsg5]

I think the 850 is overkill and performance will suffer. Can you provide the list number on the 850, it is on the front of the airhorn.