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

[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.

[Cliff Ruggles]

"Everyone I have spoke to has advised me to sell it and buy a holley."

Then you are talking to the wrong folks.  Holley carburetors, especially newer production are not good street carburetors when you care about efficiency and long trouble free service life.

We actually cause the demise of thousands of Edelbrock Performer Series and Holley carburetors by replacing them will quadrajets.  The q-jets are not only a lot more efficient, they will make as much as or more power, even in high performance and "race" applications.

We can help out with rebuild and tuning parts, best to call the shop with the part number and application and we'll get what you need headed your way.....Cliff

[429bbf]

is there any reason you took out the gm distributor , i bought one davis and it was the biggest pos I've ever owned when you get done turning the carb and if it still doesn't run right throw the dist. in the garbage , the run out on mine was so bad when you put it in the hole it bound up the rotor. fwiw