Dual Quad Manifold on 333 Heads

[DonnyO]

Newbie Here:
I have a rebuilt truck 409. Not much info on the build but we have hydraulic lifters, Likely a mild/street cam, and 333 heads.
The installed intake is a GM 3770083 single four.

Can we install an aftermarket two-four/large port manifold on these heads
(Edelbrock, Offenhauser)?

Thanks for any advice or recommendations,
Donny

 

[55Brodie]

You will need a small port intake. Offy makes one.

 

[DonnyO]

Thank You so much…I kinda figured that.
Also, would it be OK to use 2.5” exhaust manifolds? We have a LH and I do see the exhaust ports are definitely smaller on the 333 heads compared to the openings on this manifold. In any case it looks like it would seal OK. The project car has an existing 2.5 exhaust pipe system.

BTW, it’s a ‘56 Chevy SD…we would never use the real thing (stamped HP 409)
As we know you guys need those for your 61-65 projects. Years ago I had a ‘62 409/380 Bubbletop Bel Air…the one that got away. duhhhhhhhhhh!

 

[Murphdog]

Some others will know for sure but I think Edelbrock made some of there new 2x4 intakes in the small port version a few years back but not anymore. Part # 5408, I found an old listing from Speedway. Might do some scrounging!
Jeff

 

[1964SuperStocker]

Just reminder: Offy doesn't "MAKE ONE" They "MADE ONE". You need to find a vintage small port dual quad. Just about every company made a small port aftermarket intake back in the 60's-70's but they aren't really hard to find. Now Edelbrock only makes a single 4 barrel small port currently with no plans to bring back their dual quad small port intake (I have one). That Edelbrock dual quad is the best flowing of any small port intake made yet if you can find one expect to spend $1000-1500 at least. An Offy or Wiend dual quad from back in the day will run you around "500-700. There are a hand full of different versions of those with spread bore being the rarest. There are tall and short versions of those dual quad intakes as well where a 1" spacer was essentially added to get the carbs up higher. Hunt around on Craigslist, Facebook Marketplace and Ebay. If you are a year out with your build then maybe consider one of my 3D printed small port intakes I'm developing. We just started the last phase of R&D to get these intakes in the hands of the general public. Those 333 heads are great too. Stuff 2.19 intake valves in them and enjoy with a little port work to blend.

 

[fourzeronine]

Newbie Here:
I have a rebuilt truck 409. Not much info on the build but we have hydraulic lifters, Likely a mild/street cam, and 333 heads.
The installed intake is a GM 3770083 single four.

Can we install an aftermarket two-four/large port manifold on these heads
(Edelbrock, Offenhauser)?

Thanks for any advice or recommendations,
Donny

The Offenhausers were only available in the small port, so those will work.

If you are fortunate enough to find a small port Edelbrock, that'll work.

Otherwise, you can use a large port Edelbrock, but it will require the same modifications as needed to use a GM intake on small ports. Cut off the ears at the fastener holes, plug the bolt hole in the intake, and accept the port mis-match.