Square Bore VS. Square Bore

[Bodyperson]

I did not realize there was a difference until I bought a new Edelbrock AVS. It does not fit my manifold like I thought it would. Pics to follow.
I do realize a thicker insulating gasket and or a spacer that I will use will solve the clearance issue and I'm fine with that. I'm not trying to set the world on fire with this mild 340 build.

My question is... Should I live with the difference or should I mill out (gasket match) the offending aluminum? I still plan on using an insulator.

P.S. I have some experience with burr tooling.

 

[66fs]

I guess you bought a 800 cfm Edelbrock? Do the primary blades hit the intake when bolted down?

 

[Bodyperson]

I guess you bought a 800 cfm Edelbrock? Do the primary blades hit the intake when bolted down?

Yes

 

[66fs]

I'd get a used 4 hole spacer and use WD-40 and a hole saw and open up the primaries on that aluminum intake.

 

[RustyRatRod]

I did not realize there was a difference until I bought a new Edelbrock AVS. It does not fit my manifold like I thought it would. Pics to follow.
I do realize a thicker insulating gasket and or a spacer that I will use will solve the clearance issue and I'm fine with that. I'm not trying to set the world on fire with this mild 340 build.

My question is... Should I live with the difference or should I mill out (gasket match) the offending aluminum? I still plan on using an insulator.

P.S. I have some experience with burr tooling.

View attachment 1716337751

You should use the correct gasket for the intake and that ain't it.
Something like this:

Edelbrock 9266 Edelbrock Heat Insulator Gaskets | Summit Racing

Free Shipping - Edelbrock Heat Insulator Gaskets with qualifying orders of $109. Shop Carburetor Base Plate Gaskets at Summit Racing.

www.summitracing.com

 

[Bodyperson]

I'd get a used 4 hole spacer and use WD-40 and a hole saw and open up the primaries on that aluminum intake.

Thats a very good idea. I'm just wondering if I should just get a cheap speedmaster instead of hacking up what I think is a rare manifold.

 

[66fs]

Only you can answer that one brother. I would get exactly what you want, or you will always be wanting. Most any aftermarket intake would accommodate that 800 AVS2.

 

[PROSTOCKTOM]

Thats a very good idea. I'm just wondering if I should just get a cheap speedmaster instead of hacking up what I think is a rare manifold.

I always like to use a 1/2" phenolic spacer on all of my engines even if stockish. Personally I would blend it until the throttle blades fully clear.

It's not that rare of an intake and it won't hurt the value in my book.

Tom

 

[Bewy]

Five minutes with a burr would fix the problem, no spacer needed. The man is designed to take a 750 AFB carb, which has 1 11/16" t/bores. The 800 AVS is slightly larger at 1 3/4" or.......1/16" bigger....which is 1/32" bigger at the man openings. So only a very small amount of metal needs to be removed....hardly 'hacking up' the intake or removing enough metal to change the flow characteristics.

 

[Bodyperson]

Five minutes with a burr would fix the problem, no spacer needed. The man is designed to take a 750 AFB carb, which has 1 11/16" t/bores. The 800 AVS is slightly larger at 1 3/4" or.......1/16" bigger....which is 1/32" bigger at the man openings. So only a very small amount of metal needs to be removed....hardly 'hacking up' the intake or removing enough metal to change the flow characteristics.

I agree. It isn't much. Thanks for the responses folks.

 

[Bodyperson]

So I got my spacer. Edelbrock wooden heat insulator. It has a divider like the 2 plane. I'm surprised it came with 2 open gaskets, I'd think the bottom gasket should include a divider too. Am I nucking futz?

 

[Bewy]

No, a divider in a thin gasket is a bad idea. The divider could blow out during a backfire.

 

[furrystump]

Not an issue, it might like it. I would buy an open spacer and see if it likes it. Be careful with hood clearance. 1/2” can be significant. 1/4” would solve your original issue, if it has clearance issues.

 

[Bodyperson]

Not an issue, it might like it. I would buy an open spacer and see if it likes it. Be careful with hood clearance. 1/2” can be significant. 1/4” would solve your original issue, if it has clearance issues.

I will be sure to watch the hood clearance. Learned that one 40 years ago when we changed manifolds on my buddies Camaro. Seen a lot of hood dimples since then lol. I'm going to clearance the intake for the carb any way so I can always revert to no spacer or try a smaller open one or something. Thanks.

 

[BSB67]

I'm going to clearance the intake for the carb any way so I can always revert to no spacer or try a smaller open one or something. Thanks.

Do you have a wood router? If you do, you can easily do a very professional job enlarging the intake using the spacer you have as a guide for a route bit.

 

[BSB67]

 

[Bodyperson]

View attachment 1716415052

You are suggesting using a wood cutting bit for use on aluminum?

 

[BSB67]

You are suggesting using a wood cutting bit for use on aluminum?

Yes, carbide wood bit, as pictured

 

[33IMP]

Use the tool of your choice (die grinder with a sanding roll would get it done, eventually) and gasket match the intake.
Then you can run the spacer... or not.
Just what I would do.
(Thought at first it was core shift on an edelbrock. I have a Sixpack intake with horrible core shift).

Edit: uh, nevermind. Just read op's post #14. Problem solved.

 

[RustyRatRod]

Just use the gasket I recommended early on and it will work fine. But fack no you gotta hack the intake up. Makes no damn sense at all. Have at it.

 

[Bodyperson]

Just use the gasket I recommended early on and it will work fine. But fack no you gotta hack the intake up. Makes no damn sense at all. Have at it.

I don't HAVE to hack it up. That was the question I originally asked. Most say yes and you say no. I didn't notice that the gasket you suggested was that thick and insulated. I should have looked closer. BTW, I like hacking manifolds so I'll still do it either way. Certainly cant hurt.

 

[RustyRatRod]

I don't HAVE to hack it up. That was the question I originally asked. Most say yes and you say no. I didn't notice that the gasket you suggested was that thick and insulated. I should have looked closer. BTW, I like hacking manifolds so I'll still do it either way. Certainly cant hurt.

I just don't like making premanent modifications whe I don't have to. ....and you clearly don't have to. But hey, it's your intake.