1966 Olds 425 Q-jet 7026250

[455 Poncho Olds 425]

Hi, I have a 1966 Olds 425ci Q-jet 7026250.
Do You have recommendations on Replacement Inlet Valves for it ?
My Q-jet still has the Plunger diaphragm needle and seat.
I took it apart today and its a decent shape.
The Inlet valve was held down with 2 tiny screws.
The rubber tip is hard and dry.
Does not hold vacuum when I tested prior to teardown.

Can I install the later Fuel inlet valve Needle and Seat design used come 1968 ?
Drill and tapping would be required I know.
A friend can machine Counterbore the Sealing washer seat for me.

I know the 1965-67 Q-jets did not have a very good inlet valve design.

I am using this 1996 Olds Q-jet on my 1965 Olds 425 A engine.
Using an Offenhauser Intake. The Dual port O Sonic.

Thanks.

Brian R.

[Cliff Ruggles]

You will need to stick with the original set up for needle/seat.  I dont' think it's feasible to tap the casting and upgrade it to the later style, the depth of the seat would have to be precise for correct float geometry.

I'm not overly fond of the early carburetors, but they work OK if you use good parts in them and complete/correctly rebuild it.  They always leak at the bottom plugs, so expect to deal with that issue during the rebuild.

We sell kits for them, with the upgraded N/S assembly and good Viton tipped needle, upgraded accl  pump assembly, new float, filter/spring, secondary cam/spring, gaskets and small parts.....Cliff