ok i have an 1980 chevy scottdale 3/4 ton with a 350 and a 4 speed manuel, ok i have a few throttle body spacers laying around, i have an 1 inch and a 2 1/2 inch, i was wondering what would be the differents between: no spacer to/ 1 inch.. or no spacer to/ 2 1/2 inch???

 

To be honest, if the rest of the motor is stock I doubt they will make any difference.

 

it will be hard to tell the difference in power gains either way you go

 

ok how about gas performance??

 

Not that you would notice in my opinion.

 

ok so what if i cam, port and polish and re build the heads, new rings, bearings, and maybe .30 bore, what would a spacer do then???

 

I have no idea, just put it on and see if you like it, a dyno would only be able to tell the difference in my mind.

 

ok sounds like a plan...

 

The only thing a tbi spacer did for me was make my idle higher. But SOMETHING on my engine is finally shiny!

 

throttle body spacer does a little for your truck but not that much a little HP and a little gas mileage. if you have it you should just put it on. it won't hurt just to have it there and it makes a pretty cool whistling noise at lower rpms.