Headers and strait pipes

[Capt.]

I have an 98 silverado with stait pipes right from cats, and im thinking about puting full length headers on. Will the stait pipes be a problem? Also if i put full length headers on is it all basicaly bolt off and then bolt on new? Because iv hurd of people have to cut in to pipes and then get a tune and the whole nine yards.

[kjk1500]

I had edelbrock shortys on my 94 with straight pipe. It was fine never had the engine light come on or anything. With the 98 I dont realy know about the 96s and up on the tunes and engine light tho.

[loudbluez71]

If u get full length headers u will have to cut down pipes shorter ,maybe even move cats back not sure.I have herd you will not notice a difference in long tube or shorty's on stock motors.i would get shorty's with 3in pipe down to high flow cats and 3in pipe to the back with 3 1/2 or 4 inch tips.This will be a pretty penney though.

[Capt.]

Whats the benifits of high flow cats? and i allready have 2 1/2inch pipes to 3 in tips. Not going to change much of that. With High flow cats would my millage stay up or would it be like haveing no cats on?

[scaldedog]

I have a 2000 1500 Z71 and i got shorty headers, then cut out cats and added 3-bolt flanges to cats and exhaust pipes, then got y-cutouts from summit, added 3" DUAL BADLANDS electric valves and down pipes. all are welded up with flanges, I can run thru full exhaust or dump them to full open headers.(good for open road blasts or quiet for police) for any kind of inspections i just trade out dumps for cats. = all have 3-bolt header flanges on all and re-usable copper gaskets. i love to run mine open. good luck.

[loudbluez71]

Whats the benifits of high flow cats? and i allready have 2 1/2inch pipes to 3 in tips. Not going to change much of that. With High flow cats would my millage stay up or would it be like haveing no cats on?

It should heart mpg, and it is nothing like having no cats, will still keep back pressure up and not throw codes but increase sound and air flow.

[1988 GMC 355]

Why don't you search around buddy, there is tons of threads about this on here. Come on people.