yeah they were 135 a year back but now they are 200

 

Does anyone know what size down pipes the ebay headers would be able to use if I were going to make my own? I believe the factory is a wimpy 2" into the choked Y pipe.

 

Which headers? Should list outlet size.

 

I'm currently running a set of used eBay headers.

seem to be working great!

 

The ebay headers.. Stainless.. I have a pairon the way, but wondering what size down pipe i can use, because the factory ones are very small 2" . I need to know if i can go up to 2.5 " or 2.25", the reason is I will need new exhaust flanges for larger diameter pipe.

 

^^^^^^^

You could try to look it up, like HY suggested.

FWIW, I am running 2.5" pipes from the headers back.

I too had to order larger flanges to accommodate the larger pipe.

Keep two things in mind with my application that may not apply to yours:

1. I am not running the stock y pipe.
2. The headers that I purchased are not for a V8.

When piecing the whole exhaust together, I had to crack out the ol' measuring tape and find some answers for myself.

 

Thanks for the info! looks like I probably will need to get larger flanges if I go to the 2.5 pipe from headers down. I do have a new Y pipe that collects into a 3" outlet. Just wondering now to try 2.25" pipe or 2.5" pipe from headers to Y pipe. I imagine space may be a little cramped trying to bend 2.5" pipe around under tranny and oil pan, etc.

Did you order the flanges, or did your exhaust shop have them there..?

 

I am running a set from the seller you originally posted. I love mine. They are turning purple a little. They are stainless steel. they have been on my truck since May and there is no rust. There was a little prying to get the stock y-pipe to line up but for what the cost I didn't mind prying. make sure you order a set of quality HEADER gaskets. The gaskets they come with are regular stock manifold gaskets and the hardware they send you is metric and will not fit your truck. My manifold bolts were 5/16-18 so I just ordered a set of locking fasteners from summit and no problems except a leak at the flange to head surface from using cheap gaskets. I have new copper ones in my shop just haven't had time to put them on. With all that said it made a nice difference in the sound of the truck but I noticed no MPG gains nor power gains when used in a stock application.

 

has anyone had any luck finding a way to tighten that bolt that is on the inside of the pipes nearest the driver/firewall..? I have wasted a half a day fooling with all lengths and several different tools....

 

I ordered them from Napa after taking the appropriate measurements.

Flared the pipes with the torch and a cast rod.