I noticed at the u pull it that there are stainless exhaust manifolds available for the 4.x engines---usually from earlier years than the 91 deville which donated it's engine to my 85se. Mine appears to have cast iron exhaust and my question is;
Would it be of benefit to change to the stainless tubes--similar to what the 2.8 had---.
better flow?
better heat distribution?
Different sound?

If anyone has changed theirs I would like to know what your experience was.

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Proud Member of the DOWN SOUTH SUNNY WINTER drive your Fiero Naked Coalition.

85 4.9SE 4T60E Parks harness/ Rockcrawl chip-- No I do not want to race!

heres some info I dug up. I have a set of the stainless manifolds, but the main problem with them is that the exhaust flange going to the exhaust system, is smaller than the 4.9L manifolds. I think the inside diameter of the cast-iron is the same as the stainless ones, but since they were used on a smaller engine, they used a smaller exhaust, so they made the flange match the exhaust. So, either you'd have to weld on a different outlet, or block it off, and run the exhaust out the crossover ends of the manifolds. I believe they weigh less, but nobody has been able to get me some weights of the cast-iron 4.9L cross-over style manifolds.

https://www.fiero.nl/forum/Forum2/HTML/057155.html

[This message has been edited by collinwestphal (edited 12-20-2004).]