In terms of performance, The Sprints, KFG and WCF shorty's are about the same. The ported stock manifolds are slightly less, but not by much. With shorty style exhaust manifolds, expect roughly 4-8hp gain (3-6hp for ported stock manifolds.)
In terms of reliability, The stock manifolds can be re-welded and coated but can still crack. I had Sprints on my 2.8L for 7 years then moved them over to the 3.4L I did 2 years ago. They weren't as "shiny" as they were when they were new, But they still looked good and never had any problem with them. KFG's have been rumored to crack, I would search the archives.
I have never heard anything bad about WCF shorty's.
The WCF full headers are great for modded 2.8L engines (turbo, NOS, large cammed, etc.) and larger displacement engines like the 3.1L and 3.4L, But on a basically stock 2.8L you gain minimum HP and lose some low-end torque.
As for cost, The cheapest way is to port the stock exhaust.
The Fiero store sprints already come coated and if you order by phone and tell them you are a member of Pennock's you get a 10% discount on them. Basically you get $59.90 off the price.
WCF shorty's are less than the sprints but are uncoated. If you buy the coated set they cost more than the sprints.
I don't remember the cost of the KFG's but I think they are about the same as the Sprints and WCF's.
[This message has been edited by Oreif (edited 07-05-2005).]
