Technical Header Gaskets for SBC w/ Aluminum Heads

The 350 in my 47 coupe has aluminum heads; it also has block hugger headers, which it came with when I bought the car a number of years ago. Periodically it has developed an exhaust leak at the headers, which I've cured by snugging up the bolts. But this time snugging the bolts hasn't cured it, so I'm looking to replace the gaskets. On my A pickup I have stock iron heads and aluminum header gaskets (I think they're from Mr Gasket) that have worked great, never have to snug up the bolts and they never leak. I've even pulled the headers to repaint them and reused the gaskets, and all remain tight and leak free. So I was thinking of buying some of those same gaskets for the 47, but not sure if aluminum heads require a different gasket material. A google search turned up no info, so I'm checking in here to see what you guys think, what you've used with headers on aluminum heads.

Thanks!

 

The multi layered steel ones work well aluminum heads, Cometic may be the name.

 

Brodix aluminum heads. Dead soft copper gaskets ( speedway) , ultra copper silicone sealer ( both sides of gasket) no " snubbing ", no leaks , 12 years .
My unscientific , anecdotal experience .

 

I use soft copper gaskets on the aluminum heads on Plan II, seems to work just fine. I don't bother with sealer, though.

 

A thing I've done over the years and always works. With headers off, cut the flange between the ports with a wiz wheel or hack saw. It lets the header expand and contract so doesn't pull on the bolts when cool down. I usually use the stock type exhaust gaskets (Fel Pro) cut down

 

I’ve heard here on the HAMB that Remflex was the best thing going, maybe only on cast iron heads though?

 

Ive never had a leak on aluminum or steel heads with Remflex gaskets.

 

I have found Remflex is great also

 

Fel-Pro exhaust manifold gaskets will cure the problem...

 

My last set of headers I made soft copper gaskets at my machine shop gig, IIRC from .050" material. I just tightened them up and they never leaked.

 

I also like the reflex gaskets, I put them on anything that was leaking and it would fix it no problem and last a long time

 

Since I switched to stock type exhaust manifold gaskets on my cars with headers and aluminum heads, I've never had an exhaust leak again. I tighten them down, and check the bolts again after the engine has heated up and cooled down. Then again maybe a week or so later, and then forget about them.