I am Stating my LS1 swap on my 91 RS and have some header questions. I am going to be running a tubular K member without spring buckets I am running coilovers with the LS. what are the clearance isues with the 4th gen longtubes.

If is is with the stock K member will the tubular one allow them to work or is the issue somewere else

 

you can usually find pacesetter 4th gen headers really cheap, might be worth trying, but aside form that, the front end of the 2 cars is totally different, i would assume the frame rails are in the way.

 

ditto that.
build your own or pony up the money for the hawks headers.
i tried to use a set of hookers from a 4th gen and it just wasnt going to work without extensive modification.

 

One would think the tubular K-member with the coil overs would open up a ton of room.

 

It opens up room in certain areas except flow path of the exhaust. Tubular k-members do not change the fire wall or frame rail locations which prevent you from using 4th gen exhaust components (other than cat-backs; with mods)

 

Exactly. 4th gen long tubes simply don't fit in a 3rd gen.