1990 Gmc Sierra

Yummy · December 22, 2002

Hello,

I have a 1990 gmc sierra (5.7l 350, auto with o/d) I was wondering what I sould do next, I have a chip, K&N, After market exhaust 2/1/2 - 3 inches forgot( Nothing special got it off a yukon or sumthing like that.I have a powertower, and removed all restrictions, and have the engine taking in cold air from the front.

Here the deal: I dont know what to get.. I'm thinking Headers, and tru duals. (Gibson or Borla i want? heard many good things) Or maybe is their sumthing better for more hp. I dont want anything like a supercharger that for later down the road but anything will good hp gains.

Does anyone have any tips for which exhuast, headers. I heard that if u get it so it sticks out b4 the wheels u get hp gains is this true?

Any suggestion would be appreciated.

GARETH

Yummy · December 23, 2002

????

Shaners · December 23, 2002

Headers will probably give the best bang for the buck. That with a free flowing muffler will show you a 20+ HP increase. As far as brands go I don't know where to send you except to maybe the performance section of the forum. There are some great guys with good tips in there....

You don't mention what gearing you have in your truck, but if you have 3.42's I'd swap them out and you would be surprised how much better the truck performs.

Yummy · December 25, 2002

I have stock gearing( dont know what it is) ..

I have another ?

Okay what would put out better performance? a single exhaust aftermarket like gibson vs a true dual gibson ? i just wanan know what one would put out best gaisn or anyone have a website where i could read from

Also what if you taek teh muffler off would u gains more hp?

and if you dont have a cat back do u lose or gains hp? say like a performance one..

Thxs

Shaners · December 25, 2002

Headers with dual free-flowing cats - a crossover pipe like an "X" or "H" pipe to balance the pressure between the left and right banks (plus it takes some of the harshness out of the sound), then back into dual mufflers and dual pipes out the back. If I had the money and wanted a 100% legal high performance exhaust, that is the way I'd build mine. The fewer bends in the exhaust, the freer it will flow.

Also remember, in order to get the air "out", you need to get it "in" too... So some sort of low restriction air intake like a UPD or K&N FIPK would help out.