I have a 1989 Chevy k2500
Thank you for identifying your vehicle. Not many newbs do that...
Another plus on your side!
I bought 80 model headers for it and the driver side will not fit
Yup, because that's the wrong body style. The Square body routes the exhaust under the driver side, not the passenger like our 400s.
I’m was thinking if I bought 1988-1995 Chevy 5.7 headers
That's the best idea, using ones designed for your actual vehicle...
Next question: shorties or long tubes?
A: Shorties attach to the OE y-pipe and are a direct fit, especially if you use the ones with the bell flange (not the flat 3-bolt flange).
B: Long tube require custom fabrication, bending, chopping/welding, custom hangers, and may not be legal in some states. Some need to take the vehicle to a muffler shop, who may not perform the work. It's a federal offense to render an emissions device inoperable. Meaning the shop can get up to a $10,000 fine for removing your catalytic converter...
Heres 2 of my 4 trucks. Not pictured is my '00 Yukon with its iron manifolds or my '89 restoration project.
First two pics:
'95 2500 p/u 5.7 daily driver. Shorties w/OE design y-pipe
Second two pics:
'88 1500 p/u 5.7 mud truck, registered with state DMV as "for offroad use only". Long tubes and staight pipes