AVS II on a Poly?

[toolmanmike]

We are talking 4 barrels for 318's on FABO and the 650 AVS II was mentioned. I don't remember a separate discussion here about that. If you have one on your Poly, how does it work? What intake are you running? There's a choice of the stock 2 barrel with an adapter, a stock 4 barrel with an adapter (to make it work), or the Weiand 7503. The 7503 is not a dual plane but a divided plenum single plane. I am curious if the AVS II design would help with the bottom end lost because of the intake design.

 

[rumblefish360]

Not any more than any other carb. I’d use a dual plane intake if possible but NOT and adapter to make a 4bbl work with a 2bbl intake. The 2bbl intake flows only so much and the 4bbl carb flows way way more than a 2bbl intake can or ever will if modified.

The drivability of a carb is properly sized primaries (and state of tune of course)

 

[Dako]

I've had the AVS II on my '66 Belvedere II since completing restoration in 2012. It sits on a '62 OEM 4bbl intake via a 1" phenolic spacer. I've been very happy with the combination.

 

[66 Sat]

I'm pretty sure Gary Pavlovich recommends the 500 cfm Holley 2300 2 barrel carb on the 2 barrel manifold. For street use it should perform well.

I didn't have great results with my AV2 650 on a cast iron 4 barrel factory manifold, however that's on a 354 Poly stroker - maybe it will be good on a 318 poly? I can't see it helping with the bottom end using the Weiand 7503 manifold though.

I know you've been toying with installing the 7503 manifold for awhile now - I think it would be a mistake with its lack of low end torque but maybe you should whack it on there and judge for yourself. At least you'll know one way or another. People's opinions are often varied but experiencing it for yourself is always definitive.

 

[toolmanmike]

I'm pretty sure Gary Pavlovich recommends the 500 cfm Holley 2300 2 barrel carb on the 2 barrel manifold. For street use it should perform well.

I didn't have great results with my AV2 650 on a cast iron 4 barrel factory manifold, however that's on a 354 Poly stroker - maybe it will be good on a 318 poly? I can't see it helping with the bottom end using the Weiand 7503 manifold though.

I know you've been toying with installing the 7503 manifold for awhile now - I think it would be a mistake with its lack of low end torque but maybe you should whack it on there and judge for yourself. At least you'll know one way or another. People's opinions are often varied but experiencing it for yourself is always definitive.

Interesting. He's the man when it comes to Poly's. I sold hundreds of those 500 2 barrels back in the day. Simple carb. Takes an adapter too, plus a box of other goodies. My 2 barrel works fine now and it may not get changed. I'm an easy driver. I don't need to burn tires. I'm past that. I'm more about a comfortable seat and power steering. May be AC someday. My intakes will sell well at the swap meet.

 

[pro451bee]

I put a 500 on my coronet in the 80s and everyone wondered what I did to that wide 318 caused it it did run good. Great response and the kick down was good too