Scored Offy dual quad intake for my 392 WEDGE project!

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Thanks for the heads up on the ModMan intake. Doesn't it require a special offset distributor to fit? I think I remember reading about that in a thread discussing running a blower. If I remember right, there was an intake made in Brazil that actually fit the bill for that.

YR, you wanted some pics of the intake gaskets matched up on the intake. In these pics, I am using the larger FelPro 1213 gaskets, 2.27"x1.16". I matched the bolt holes as best as I was able by eye. The head that I grabbed is a 302 head, planned for interim use until I can get the build done on my other block.

If I want to gasket match these heads, I will need to add material to the outsides of the runners to maintain wall integrity. I will not be able to match those 302 heads to these gaskets. If needed for more pictures, I can grab the smaller 273-318 gaskets (I probably should anyways for the 302 heads), P/N 1243 dimensions 2.08"x1.05".

Thanks for all the help on this. I've looked around, and I've seen plenty of this manifold on ebay, so guys with an older 273 can get these. That relieves me some about chopping on this bad boy.

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Right rear
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Right front
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Left rear
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Left front
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Howdy. Long time moparts member here but new A bodies member. Im glad and sad I found this post. In 2002 I bought a brand new Offenhauser 2x4 from Summit. Its for the later 273 not the earlier oddball mounting hole config. I have been buying and storing parts for my 360 Demon since 2003. My child support obligation is concluded in 2 months and I am actually moving fwd with my Demon. (Note I sad child support obligation not father obligation). I knew the 273 manifold would not be optimal on a 340/360 but want that early 60s nostalgia none the less. MiradaMegaCabs post mad think oh s#@!. If I cant make the 2x4 Offy work then Ill probably do an RPM and a Street Demon carb but man! My goal is a daily driven near manit free Demon capable of low 13s in street trim- so I would hate to run a Weiand tunnel ram on a 13 sec car. (Six pack too expensive!!) I was actually awaiting Edelbrocks release of their 500 cfm AVS2 so I could purchase a pair of them. Part number 1902 is due out march 6 2018 but keeps getting pushed further out.
 
Michael Harrington said:
Howdy. Long time moparts member here but new A bodies member. Im glad and sad I found this post. In 2002 I bought a brand new Offenhauser 2x4 from Summit. Its for the later 273 not the earlier oddball mounting hole config. I have been buying and storing parts for my 360 Demon since 2003. My child support obligation is concluded in 2 months and I am actually moving fwd with my Demon. (Note I sad child support obligation not father obligation). I knew the 273 manifold would not be optimal on a 340/360 but want that early 60s nostalgia none the less. MiradaMegaCabs post mad think oh s#@!. If I cant make the 2x4 Offy work then Ill probably do an RPM and a Street Demon carb but man! My goal is a daily driven near manit free Demon capable of low 13s in street trim- so I would hate to run a Weiand tunnel ram on a 13 sec car. (Six pack too expensive!!) I was actually awaiting Edelbrocks release of their 500 cfm AVS2 so I could purchase a pair of them. Part number 1902 is due out march 6 2018 but keeps getting pushed further out.
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I’m kind of missing the point or question of this post but...

What you have is an early 273 and a later I take?
It is possible to still use it on the newer intake bolt angle. Some have made wedges to install under the bolts. I feel thread sealant on the bolt threads and a dab of gasket sealer/maker under the bolt head would seal it up.

Pretty? No
Workable? I think so.

Also, IF this is connected to a 360 head, I have no idea of you can port it out to the same size as the port. Ports vary head to head. After market heads being the widest and tallest. I would go as wide and high as possible and the floor last.

A smaller port than the heads opening isn’t the end all and hugely bad. It is better than not opening it up at all. If anything, velocity will be up which will help throttle response and mileage under part throttle cruise.

Getting into the 13’s should take much. If a 318 can do it (and funkin-A it can!) through it’s small ports...... your 42 extra cubes can do it and at a slightly lower rpm. Don’t worry about choking it out.
 
I have the manifold for the "1966 and later" 273 so the bolt holes are correct for 360 heads. The sealing surface around the ports on the manifold- may not be sufficient when bolting to a 340/360 head because the ports on the bigger LA motor are MUCH larger than a 273 and the offy manifold. I guess its like a bolting a standard 440 manifold onto some ported max wedge heads. I put a blue Felpro 360 gasket up to the port surface of the Offy and theres very little sealing surface- aluminum on the top of the runners/ports. I can try a 318 gasket after i buy some and see what that looks like. Probably same issue but in a different area.

offy gasket.jpg
 
How much metal is behind the gasket?

FWIW, I’d still run it.
 
Right side up pic. Sorry for the purple hue- old HTC phone. There is very little gasket covering the sealing flange surface of the Offy. Like was mentioned previously the flange would need to be built up with weld and machined to be proper. I wont have that done. 13s is a 1/4 mile goal simply because it will be a mild build and hopefully ultra reliable with no fuss. My back cant handle heavy duty repairs. Just be nice to do a budget build and get back into the hobby. Been almost 20 years since I was in the hobby.

offy gasket 2.jpg
 
Ooooh oooh oh oh oooh !!!!

Your Funkin in like flint! More than enough Spaghetti sauce to spread around there!

Port and run!

Your only fooling yourself otherwise!!!
It’s a freakin GO!
Open that baby UP!
OMG! Hell yea!
Just watch the lip!
 
Is that shot upside down?

I’m getting confused! LOL

Bottom line, I’d run it as is if it really is on the boarder and just cam it!
Let’er Rip potato chip!
 
Pic is right side up manifold is upside down in my table. Potato chips are cool. My pics match the previous pics posted here just mine are not clear.
 
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Michael Harrington said:
Pic is right side up manifold is upside down in my table. Potato chips are cool. My pics match the previous pics posted here just mine are not clear.
Click to expand...

Michael welcome to FABO.
Perhaps PM Teringer as he also has experience with welding one of these manifolds. It's a common problem when used on 340/360 large port heads.....
Best of luck on your project
 
It could just be the picture but it look like the top is on backward, they are milled at a angle and the back should be higher than the front. When installed the carbs are level because the motor tilts down in the back.
 
Probably is backward.. Its just a kitchen ornament right now. I dont understand why Offenhauser didnt beef up their manifold mounting flange for the 340. The 340 came out in 1968 of which Offy was alive and thriving then. I look forward to this tunnel ram. I will have the cam, compression and stall to make it work. Carbs are remanned Edelbrock 500s from Summit. Or if one prefers: "ELDerbrock."
 
Offenhauser did have two different port size intakes in there line up years back. 273/318 size and 340/360 sized ports.

Offenhauser got lazy and stopped updating and creating.
Weiand is in a state of sleep. Now owned by Holley, they’ll do nothing with them.

In a way, it is a shame that Edelbrock is the only real manufacturer and currently trying very hard to Innovate and create and you push forward on designs for the automotive industry in the high-performance field. There are a few other companies like trick flow that are doing stuff, but at a much lower and slower rate.

You should really like that T-ram.
 
Rumble the tunnel ram is a complete Edelbrock street unit top and bottom made in the early mid 90s. I noticed the plenum 2x4 style top of the weiand 340 tunnel ram is massive but the top of a Weiand TR for small chevy is not. Why is that?
 
Michael Harrington said:
Rumble the tunnel ram is a complete Edelbrock street unit top and bottom made in the early mid 90s. I noticed the plenum 2x4 style top of the weiand 340 tunnel ram is massive but the top of a Weiand TR for small chevy is not. Why is that?
Click to expand...


Different engineers had different ideas. I'm not a big fan of huge plenums on tunnel rams.
 
A huge plenum is t needed for the street
 
Rumble- I post while on break at work and have a million things on my mind. My tunnel ram is the Edelbrock Street tunnel ram with the dual 4 bbl top.I was gonna buy a weiand tunnel ram but a moparts member reached out to me with his old but never used Edelbrock unit and I got it!!!. Forums rule! I already gasket matched the ports and set a pair of remanned Edelbrock 500s on them. It will sit on my counter until spring 2019 when it goes on my 360.
 
Thinking out loud here. Mopar 340s and chevy 350s are very similar engines but Weiand makes their tunnel ram for the mopar with a very large rectangular upper plenum while the 350 chevy gets the more common and smaller tulip shaped plenum. Chevy TR top pic- mopar TR bottom pic.
chvy tr.jpg
1995.jpg
 
I have the smaller plenum in my tunnel ram. You can swap tops. Edelbrock to Edelbrock.
I also have a M1 t ram. It has a lot of plenum. All the M1 tops are the same.

A lot of plenum vs a little bit of plenum?
Is that the question?
 
Hey Rumble. Kind of. My interest is that the 350 chevy and 340 mopar are very similar in head flow, valve size , port size and of course displacement. With that Weiand makes their Chevy Tunnel Ram with a smaller top and their mopar unit with a big coffin like top. Just wondering what why Weiand did this.
 
I can’t say why one manufacturer does one thing over an another.

A larger plenum would be a move to a higher rpm operating range and a larger engine.

A smaller plenum would bennifit a smaller engine, lower operating rpm range. (Not that high rpm would be a problem) A better throttle response for the street would also be available with a smaller plenum, reduced jetting as well.
 
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