Header Interference?

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royalbull73

royalbull73

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Installed new Doug's headers on my 72 340 demon and see that they are touching the torsion bar on the driver's side and touching the bell housing on the passenger side. Could this be a problem? Do I "dimple" them in with a hammer? Hate the thought of beating on new ceramic coated headers but thought I would ask the group first to see what the general consensus was.

Thanks

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I wouldn't dimple anything before I triple checked engine sitting where it belongs and motor mounts in excellent condition and even then I would hesitate.
 
A small relief massage on the header wouldn't hurt if you have to.
 
I would grind a tad off of that bell housing just need 1/16 inch cause header and eng/trans move together.

Loosen motor mount k-frame nuts and see if you can nudge the engine toward the passengers side a bit. A shim between motor mount and k-frame can help. Factory k-frame tolerances very sloppy so engine probably not sitting in car in correct location.

I run one of these to limit engine movement, keeps headers from hitting things, and does not add any vibrations:

'66-72 B-Body, '70-74 E-Body, '67+ A-Body Torque Strap

I don't think any dents are going to be needed.
 
318willrun said:
A small relief massage on the header wouldn't hurt if you have to.
Click to expand...

Like I always say, the biggest difference between really expensive hedders and cheaper ones is it hurts more to ding the expensive ones.

I will add though, I have adjusted motor mounts as little as 1/8 inch up down or sideways to get an 1/8 clearance on both sides.
 
TrailBeast said:
Like I always say, the biggest difference between really expensive hedders and cheaper ones is it hurts more to ding the expensive ones.

I will add though, I have adjusted motor mounts as little as 1/8 inch up down or sideways to get an 1/8 clearance on both sides.
Click to expand...
The Doug's on my '76 Duster didn't need anything, fit like a glove. However, the Doug's on my '74 Duster needed the #5 & #7 pipes massaged in the exact location as the OP's, by the drivers side torsion bar. But, it has the /6 to V8 schumacher conversion mounts and I perhaps didn't get it set exactly like factory. Didn't bother me a bit to put a little relief in the pipes though.
 
318willrun said:
The Doug's on my '76 Duster didn't need anything, fit like a glove. However, the Doug's on my '74 Duster needed the #5 & #7 pipes massaged in the exact location as the OP's, by the drivers side torsion bar. But, it has the /6 to V8 schumacher conversion mounts and I perhaps didn't get it set exactly like factory. Didn't bother me a bit to put a little relief in the pipes though.
Click to expand...

Yep, it’s tight in that engine bay when it comes to hedders.
I have 1.03 torsion bars which makes those clearances even tighter.
Sometimes I think about mounting the motor solid since about everything else shifts position after awhile.
Just can’t bring myself to do it.
 
TrailBeast said:
Yep, it’s tight in that engine bay when it comes to hedders.
I have 1.03 torsion bars which makes those clearances even tighter.
Sometimes I think about mounting the motor solid since about everything else shifts position after awhile.
Just can’t bring myself to do it.
Click to expand...
i agree, and I thought of that..... "if I had bigger torsion bars, I'd have to straighten how the engine sits"
 
I'm about 95% sure you can adjust the mounts and regain enough clearence on the torsion bar and not have to ruin the ceramic coating on your headers. It won't help with the bell side but a grinder will. Just round the edge a bit.
Take your time, don't rush it.
 
TrailBeast said:
Yep, it’s tight in that engine bay when it comes to hedders.
I have 1.03 torsion bars which makes those clearances even tighter.
Sometimes I think about mounting the motor solid since about everything else shifts position after awhile.
Just can’t bring myself to do it.
Click to expand...
and that's why I'm retaining my factory 340 '69 cast iron manifolds when I go to the MP 1.14's
 
318willrun said:
i agree, and I thought of that..... "if I had bigger torsion bars, I'd have to straighten how the engine sits"
Click to expand...

I have spool mounts with factory style rubber with the air gap sections in them.
They move quite a bit.
I pounded two pieces of 3/8 fuel line into each air gap on both mounts.
That kept rubber but firmed the mounts up so the motor doesn’t move around as much.
Worked great.
 
TrailBeast said:
I have spool mounts with factory style rubber with the air gap sections in them.
They move quite a bit.
I pounded two pieces of 3/8 fuel line into each air gap on both mounts.
That kept rubber but firmed the mounts up so the motor doesn’t move around as much.
Worked great.
Click to expand...
I taped the back side of the holes and filled a pair with 100% silcone caulk.It had the same effect.
 
Deltatech said:
I taped the back side of the holes and filled a pair with 100% silcone caulk.It had the same effect.
Click to expand...

I considered doing the silicone, but waiting until that much silicone set up was the deciding factor.
I figured 3-4 days of dry time.
 
Wasn't exactly mentioned this way, loosen the three bolts on the motor mount brackets at the engine block, both sides. You will be surprised at how much you can move your engine around. Yes, engine hoist needed, and an extra body or two wouldn't hurt. Do not think you'll gain alot from just the single motor mount bolt, but it all adds up!
 
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