Are Ls1 fans direct bolt on on a 2003 RCSB or would i have to modify them. 28" radiator.

 

They fit the smaller radiator the best yes..I think you have to make a small bracket or 2,nothin major..

 

Yes, the worst that could happen is theyre a tad bit small, might have to use some good zip ties or a metal bracket to hold it over the rad, whatever way you can rig it up

 

Ok so the 05 fans are probably the way to go?

 

For a direct fit yes, but you would have to get the larger radiator

 

I just made 2 little brackets with strap metal. I chose LS1 fans cuz I got them super cheap and I didnt have to get new radiator. I also built my own harness and they work flawlessly.

 

Same here. The LS1 fans fit the 28" radiator like stock...almost.

Like shown above, use some steel brackets as the zip ties, even ones made for tranny coolers (like I originally used) WILL loosen up and allow the fan to move around.

 

Read SnakeOiler's quote. david0982, you're confusing things a bit as they're 2 different questions. If ya wanna stick w/. your stock rad, get LS1 fans. '05 -up use 34" rad. Some like the LS1 fans cause they're cheap to get, & don't req. a rad. upgrade.

Nice clean install, looks good.

 

what all was part of your homemade harness?