Edelbrock 1406 vs 1906

[live4theking]

On my 68 NYer with a 440. The stock Holley 4160 has throttle bores that are 1.56/1.56 (primary/ secondary) the AVS that my manual shows as an option 1.69/1.69. Edelbrock 1406 are 1.44/1.69 and the 1906 AVS2 are 1.44/1.75.

Does anyone know what the whole size is in the stock intake? I'm trying to see if I'll need a spacer/ adapter.

 

[CBODY67]

The "one year only" 750cfm 4160 for 1971 383 HP was 1.56/1.75. Don't worry about a real spacer, just get the OEM-thickness carb gasket for the '70 383 4bbl and it probably will be fine. That's the base gasket with the bushings in the stud holes and is divided down the middle. Should be in either the Holley or Edelbrock catalobs, still. Then if that .06" bigger diameter secondary throttle plate is an issue, you can trim the gasket?

CBODY67

 

[live4theking]

The "one year only" 750cfm 4160 for 1971 383 HP was 1.56/1.75. Don't worry about a real spacer, just get the OEM-thickness carb gasket for the '70 383 4bbl and it probably will be fine. That's the base gasket with the bushings in the stud holes and is divided down the middle. Should be in either the Holley or Edelbrock catalobs, still. Then if that .06" bigger diameter secondary throttle plate is an issue, you can trim the gasket?

CBODY67

Thanks. That's a great idea about the thick gasket.

 

[CBODY67]

The Edelbrock #12410 (5/16" insulator gasket w/studs) is similar to what I was referring to, but with no center divider. Says it's good to 1.75" throttle bores.

Edit:
The Holley 108-18 is what my '70 383 "N" uses. Holley claims it's good for 1.75" throttle bores. A single thich "insulator" gasket, with metal bushings in the stud holes. It has a divider down the middle, frt to rr.

CBODY67

 

[live4theking]

The Edelbrock #12410 (5/16" insulator gasket w/studs) is similar to what I was referring to, but with no center divider. Says it's good to 1.75" throttle bores.

Edit:
The Holley 108-18 is what my '70 383 "N" uses. Holley claims it's good for 1.75" throttle bores. A single thich "insulator" gasket, with metal bushings in the stud holes. It has a divider down the middle, frt to rr.

CBODY67

Thanks, I'll take a look at these.