carb selection year for best result

[Stripes]

I have a 1969 Firebird with a 455 over 60 engine, 3:55 gears, stock intake, and I believe a 068 cam (212/225 @.50, .410 LIFT), RA3 Exhaust, 2.5" duels w h pipe, 400 turbo. Running 7k3 heads, stock lower end, about 9.5 to one.

I plan on adding aluminum E heads and a 60919 cam, 2400? stall converter, and a 700r4.

Should I rebuild my 1969 Carb or will a later model carb improve performance? IE I'm sure I could find a 76-79 Rochester to invest a rebuild in if it results in superior performance than redoing my 69 Rochester.

[Sonny]

I am too new at this to offer you guidance but the first question the experienced folks here ask is what is the model number and build date code on your current unit and what modifications have already been made to it?

[Stripes]

What I am asking is from a performance perspective, do later years (70-80) offer any performance benefit that a 1969 Rochester doesn't. I realize all carbs benefit from rebuilds, etc, but I am asking the question of potential. Should I build a 1969 Rochester, or will I get superior performance from a later year carb?

[429bbf]

i believe you can get about any one of them to perform i prefer 78 and newer the bodies are so much better and the bottom plugs and better sealed . i built a 69 for a guy the casting was so brittle i couldn't tap and plug the bottom plugs the casting tried to crack so i marine texted the holes and plugs and reinstalled them and applied marine text on top to get them to stop leaking. fwiw

[StillLearning]

My 69 carb is on the wall. '76 and later are better and more versatile. If you are a serious builder find a later unmolested carb to rebuild.

[Jase]

i believe you can get about any one of them to perform i prefer 78 and newer the bodies are so much better and the bottom plugs and better sealed .

Would this recommendation include the 1980-86 Truck carbs that are not Electronically controlled? I understand they have different air bleeds... But there are a few at the local salvage yard..?

[429bbf]

you can use them i actually built a couple of them . if i remember correctly they have a port from the bottom in the secondaries that goes up into the secondary housing . i tapped the hole from the bottom and installed a set screw with bearing mount . this made it just like other carbs . the castings are very nice to work with. if i remember right the numbers were 17085004 or 5 don't keep track of that stuff i just build them to use on what I'm putting it on . get all your parts from cliff .you won't regret it . i was waiting for a kit from him and got in a hurry and used one from napa. the plunger swelled up and fell off the acc. pump in 20 minutes .fwiw.

[Jase]

Ok I will go ahead with the late production carbs.. Thanks for the insight on the secondary port work, i will keep that in mind and look for it.

Agreed about the Napa stuff.. I got two carb kits for A couple of monojets, and the acc Pump lasted maybe a week.