Nothing wrong with a throttle body spacer for TBI. Don't expect much, but it does help. I suggest only using the smooth ones. I used fuel line extensions on my truck. While you are at it, might as well port the throttle body and get a pod spacer. I also suggest getting rid of the choke collar and either using a Hypertech Powercharger or a homemade version. All of that should give you a nice noticable gain. For those that say none of that won't work, I beg to differ. I haven't just read it on the internet, I have done it all to my truck. And if it makes a good noticeable difference with a V6, I'm sure a V8 will benefit from it. But I can honestly say I haven't used a throttle body from a 454. And unless you are making a good bit of power, you won't see any increase of power over a ported 262-350 throttle body. I wouldn't even consider a 454 throttle body until atleast the 300 hp range. I'm willing to bet even then it won't make a difference.