I am going to be running a single 4" exhaust and I am trying to tie two 2-1/2 inch pipes to it without too much of a hassle. I have been looking for a merge/y pipe that will work but I cant seem to find anything. Has anyone seen one out there or am I going to have to make my own?

Flowmaster might make the merge connector. The part number would be something like 250400.

No luck, they have 3" to 4" and 2-1/2" to 3-1/2". I may just have to go wuth the 2-1/2 to 3-1/2 and just step it up to 4 with an adapter. Kind of sucks.

Actually the 3.50" pipe is almost identical in area to two 2.5" pipes. So you will not be losing much. Remember the further away from the heat source(engine) the cooler and denser the exhaust gas becomes. So you do not need as big a diameter to flow the same amount of exhaust gas.

I ended up making one. Put the 4" pipe in a vice and ovaled it installed the 2 2.5" pipes in the end. Creased it with a chisal and welded it up.

Well I just made one...easy enough. I used a vice, ball peen hammer and a welder...done.

"Well I just made one...easy enough"

Hehehehe. I love it. Looks like you did a nice job of it. Hot rodding at its finest.

Thanks!
Now I just need to get the rest of the bends and muffler to get this 4" exhaust done. I just couldn't take the resonance of the dual 2-1/2's exiting under the car...that and they scraped on just about everything.

Nice looking piece of work.

But I'm having trouble connecting the dots.
What kind of 4" muffler, mounted where, with
what kind of tailpipes. I assume no cat(s)?

Throw up some pics of progress, and final product.

I am planning on using a 4" dynomax round ultra flo muffler. I will be putting it in the stock location (under the gas tank) I have a sumped tank but it looks like it will still fit with plenty of room. I will bee running one 4" tail pipe exiting on the drivers side.
I will try to get some pics up. It is a custom setup but pretty much like the mufflex system.

it's not that hard going from dual 2.5 to 4, i had to merge dual 2.5 to 3", rigt under the passanger side header