SB Dual Port Offy Manifold

[Josecuda]

I’ve been offered an Offenhauser Dual Port intake manifold for cheap. I’m building a 360 looking for good low end torque and mid range power. I was wondering if anyone had ever used this type of manifold before. Any past experiences and opinions can be helpful information in order to take a decision on buying or not. Thanks!

 

[Josecuda]

Some pics.

 

[ocdart]

Wow! I haven't seen an Offy Dual-Port in years!
I ran one on the street back in the early '70s on my old '69 Dart 340 Swinger and was very pleased with the performance. It was kind of a 'super' dual-plane intake manifold.
I was impressed with the engineering design concept of the small primary runners for high-velocity intake charges and the isolated larger secondary runners for a cooler intake charge when the carb secondaries opened up. Being smaller than a full intake runner also kept the cooler secondary charge at a high-velocity.
My 340 was built to the extent that it required a Holley 850 double-pumper to keep it fed or it ran out of gas on the top end. I was also running a full reverse-pattern manual-shift 727 and 4.89 gears - all on the SoCal streets. I loved picking on big-block Chevelles!
Sorry, I don't have any 1/4-mile times or speeds for you. All I can tell you is it worked and it ran strong.
The funny part is that I walked in to J&N Speed Center in Whittier, CA, with the intent of buying an Edelbrock single-plane ('Tarantula' I think it was called) and walked out with the Offy Dual-Port 360 because they didn't have the Edelbrock in stock. If I remember correctly, I sold the Offy for $25 at a swapmeet at OCIR when I decided to take my old Dart off the street and build it strictly for the strip.

 

[JR]

I ran one on a mild 360 daily driver for years and loved it. I just sold it (stripped threads and all) for $30 at a swapmeet.

 

[grimreaper]

I had one on my 77 W-150 with a 360. It was perfect for that application.

 

[cudavert]

I also used to run one on a street 350 pontiac.....responsive and nearly 20 MPG! I was pleased with it. It may not be the best in the top end dep't, but it worked well for me. Pulled hard.

 

[bOb shingler]

i'm thinking with a port match and tapering the dividers that would be a BAD street manifold, as a matter of fact i wouldn't mind having that on my 318 truck motor.

 

[cudavert]

i'm thinking with a port match and tapering the dividers that would be a BAD street manifold, as a matter of fact i wouldn't mind having that on my 318 truck motor.

Well, since you brought that up......*ahem*.....here's mine for $85. It's designed to fit the taller port heads on 4 barrel 318's, 340's and 360's.