I need suggestions on which headers I should put on for my 2005 4.8 I really like the JBA,Gibson but also Edelbrock.Should I replace my stock cats to hi-flow cats? Thanx

 

I would go with edlebrock to save some money, and leave the stock cats. There is only 1-2 HP to be gained by cutting them out.

 

How hard was it to bolt on the edelbrocks and how long did it take u??about how much hp and torque will I gain with magnaflow cats?thanx

 

Did not take long to put on, maybe 30 min. The hardest part was getting the original collectors loose as the bolts are hard to get to. You also have to disconect the steering linkage. The rear bolt on the driver side is a little tight, and you have to modify the the heat shield on the passenger side a little with a hammer. Overall very easy. If you look at the post titled "christmas presant" that I posted last december you can see some pics and a full description. As far as gains, they are mostlyin the high end. I installed them the same time as I did the CAI, so I can't give gains related only to the headers. But my truck is fast as hell from 2500 rpm up.I don't know about gains from high flow cats personally, but from all I have talked to there is not much to be gained there, and doing the exhaust from cats back will save fuel and give you plenty of flow. I actually have way too much flow and am having to restrict the exhaust to get back my low end. So there is plenty of freeing up to do there.

 

the guy that owns my local muffler shop told me hi-flow cats are a waste of money. and i was going to buy some from him... so i'd say they're a waste of money. either that or he is an absolutely horrible salesman.

 

I have heard from several people, including the owner of an exhaust shop, that buying headers is not worth the gain at all. Especially since the exhaust manifolds on Chevy trucks are pretty decent from factory. It just doesnt seem like 1 or 2 horsepower is worth $300+.

 

JBA has dyno charts for the 5.3,99 5.7,6.0 and the 8.1 www.jbaheaders.com