Does say an Iroc Z or Z-28 have a bigger Y-Pipe than my 305? or am i stuck paying the 100+ dollars for one that some company such as Hooker or Hedman made?

Considering 305s were also available on IROCs and Z28s I would say no. But get a second opinion. If you're getting headers you'll have to get a new one though.

My 85 IROC is an LG4 305. The y-pipe is tiny! Check out my post LG4 Exhaust Pics. You'll see that the L69, which is the HO 305, was much larger.

James

Hey Justin I just took the stock Y pipe off my 88 IROC Z TPI 5 speed its the big diameter one in good shape... you can have it for $50... i upgraded to these

Oh yeah Half the reason am willing to sell you it is because you live in cincinnati ohio and thats where i live... how close do you live to the beechmont/eastgate area???

I live in the eastgate area, about 5 min from the mall. We should get together sometime. oo and if i can get the $ together ill prob get that pipe from ya.

Another thing. You will probably need his manifolds too. The TPI ones are better(so I've heard) plus I'm not sure if your stock ones will work with his y-pipe.

Im planning on getting headers from Heddman but i didnt wanna spend the extra 100$ for their y-pipe so i figured if those were bigger then id save myself some cash

Do the Heddman's fit the stock y-pipes? Or are you just going to get it modded to fit?

Whenever you get headers, you have to get a new y-pipe, or one that isn't designed for manifolds. I believe.

I've called hedman about their headers. they said that all of them will need a new y-pipe. the stock one won't fit.

i have the hedman headers..and y pipe..word of advice tho...the y pipe is in 2 peices...and you bolt part of the y pipe up to the drivers side header flange..then the pass side heaer flange..and the rest of the y pipe slips onto the drivers side y pipe thats bolted to teh headers...now..the key to get them to fit perfectly with no leaks...{i had to do this..i dont know if all are like this} is the smaller peice of the y pipe that bolts to the drivers side header..take a hacksaw..and cut about 7/16ths off the pipe..so that the other peice of the y pipe will fully slide onto that pipe..if not..it hits the inside of the pipe.and then you cant bolt up to the passneger side header.any of that make sense..lmao.my headers and y pipe are about 5 months old or so...and heres what they look like..no leaks at all tho..sounds great with 3 inch 40 series 2 chamber flows.no cat ov course