Quadrajet Problem Solving > Diagnose a Quadrajet carburetor problem

Good jet/hangar/rod combo so start with...

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baxternick:
I have a 500 that I just got back on the road in my 54 chevrolet car. The setup is MTS 15 cam (Advertised duration range: 286-295* / Duration @ .050” range: 234* / Valve lift range: .540-.560), bored 30 over, shaft rocker system with increased ratio to 1.7, performer intake, and a stage 2 Q jet from Jet Performance. I have roughly 500 miles on this new build. The engine pulls great, but seems to fall flat on the top end.  I have a Davis DUI dizzy on the car and my base timing is 12*. I was expecting gobs of power and this feels like any other small block. Just cruising around the car is good. Just feels flat at WOT. I pulled the carb apart to check the jets and rods they put in and found the following...
Primary Jet 75
Primary Rod 50M
Secondary Rod DA
Secondary Hangar B

Jet Area at Cruise is 2.4536
Jet Area at WOT is 3.4

Just curious if this seems like a normal starting point for the cam and engine I have?
Thanks in advance for any help.. Also can you quote me pricing for the parts needed if you recommend any to 28546.

Cliff Ruggles:
Could be a number of things.  What size needle/seat assembly is in it?.....Cliff

baxternick:
Cliff,
Other than a old rochester 1bbl on my 235 straight 6 this is my first dive into a carb.  All I have other than what I posted is the model number off the side of it..  17059206 From what I understand it is a 79 model truck carb.  Everyone I have spoke to has advised me to sell it and buy a holley. I would rather fix it if possible.  Could you just work me up a price for a new needle seat and whatever else I would need to put it to a spec you would use as a good starting point?
Thanks,
Nick

Marx3:
that carb is a large mab unit.
Dont listen to the nay-sayers on cadillacpower :-)
With pretty basic mechanical skills and Cliffs parts you can make this carb act like fuel injection.
I know. I have done it many many times. Also on 500's

baxternick:
According to Jet they used a .135 needle and seat.

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