exhaust manifold question

[fireguyfire]

Just finishing the rebuild on my slant 6 in my 1970 D100; I am in the middle of a full restoration on the truck.
I have sand blasted and painted with Eastwood cast exhaust manifold paint my factory manifold. It is in pretty good condition, the exhaust "damper" opens and closes pretty freely, but as is normal the spring for the "damper" is broken (1 of the ends busted off).
Ive been getting input on my engine rebuid on the slant 6 forum, and several guys over there have suggested I buy the Dorman replacement manifold because it will not be warped, the "damper" will work properly, and it wont have the choke well that is hard to seal up.
I am in Canada and this manifold is going to cost me $500; my budget is tight as I am rebuilding the entire truck, and if I can get away with putting a new spring on the exhaust manifold damper (if I can find one) and seal up the choke well properly I cant see justifying spending that kind of money right now.
Anyone have any opinions on this? I would appreciate it!

[Jim100]

Remove damper and plug holes? I wired one open on a 318 one time with a missing spring. Not really correct if you are doing a restoration.

[sledgehammer]

Yikes, That is a lot of money! Is that the little spring that is about a half inch long? I just through one out a couple months ago.

[fireguyfire]

No, it’s the larger spiral cooled flat stock spring

[dodgeboykim]

If you want to go with a NOS Chryco SL 6 exhaust manifold I have one.

[LuckyBaldwin]

There'a a company called Omix ADA that makes resto parts for old jeeps. Some of their parts work on our mopars. They make a replacement heat riser spring

http://www.omix-ada.com/exhaust-manifol ... odels.html

not sure if this one will work or not. You might call them and get the dimensions of their spring and compare it with your original. Good luck!

[Kaegi]

I would just replace the spring. did you separate the intake and exhaust? if not they should be lined up together nicely. slant 6 are not know for warpage. thats a chevy, ford and Toyota problem. ;/) I did manifold work for years. 95% that needed workwere FE fords

[fireguyfire]

Both manifolds are separate, sand blasted and painted.
I understand they don’t repop that spring so I will try and hunt one down.

[hmaynord]

did you separate the intake and exhaust? if not they should be lined up together nicely.

please explain this more

[fireguyfire]

I think he means to ensure they fit together properly when you bolt the 2 manifolds back together to make sure they seal properly; I went with a much higher quality after market exhaust gasket set so it should be fine.
I'm thinking I'll just try and track down that heat riser damper bi metallic spring as everything else seems pretty good on my manifold.

[coelcanth]

do you have the dimensions for your spring ?

i bought a heat flapper rebuild kit for my LA318 but most parts didn't end up fitting so i just removed it all..
still have the new parts laying around somewhere.. maybe they were meant for the /6 manifold ???

this was the kit i got:

[fireguyfire]

That large circular spring is what I’m looking for!

[Kaegi]

did you separate the intake and exhaust? if not they should be lined up together nicely.

please explain this more

the intake and exhaust are bolted together then machined as one so when you bolt it to the engine it doesn't crack. its ok to take them apart but before you tighten them back together all the way bolt them to the head just enough so there is no slop. then fully tighten the 4 bolts that hold intake/exhaust together, then remove and install gaskets on head. I always use Walker Acoustiseal on all manifold installs. its a bit pricey but napa has it.
if you buy a new intake or exhaust and use with your old other you may need to get them machines before installing

[hmaynord]

did you separate the intake and exhaust? if not they should be lined up together nicely.

please explain this more

the intake and exhaust are bolted together then machined as one so when you bolt it to the engine it doesn't crack. its ok to take them apart but before you tighten them back together all the way bolt them to the head just enough so there is no slop. then fully tighten the 4 bolts that hold intake/exhaust together, then remove and install gaskets on head. I always use Walker Acoustiseal on all manifold installs. its a bit pricey but napa has it.
if you buy a new intake or exhaust and use with your old other you may need to get them machines before installing

thanks for all the detail Kaegi
I may need to do this

[Kaegi]

also use the acoustiseal between the intake and exhaust as well.