does anyone know why there is two different part numbers for throttle bodies from BBK for different years.........one is 85-88 and the other is 89-92 (on BBK website)...i was wondering because i am going to bid on ebay and they have them listed three ways there.....85-88, 89-92, and the 85-92....i don't want the wrong one...but couldn't find any info on the difference in them...

 

'89-92 throttle bodies have a progressive rate thottle linkage.

 

Progressive what?

IAC holes/EGR holes are different bewteen the years, something about how the throttle linkage/ hooks up is different too.

What year plenum are you using...that's the wild card to make sure the passages worlk right.

 

either throttle body will work on the plenum, they adapt the same way, the only difference is the throttle cable attachment, it has to match the year of cable you have in your car. 85-88 and 89-92 are different. the 89-92 have progressive rate linkage, i prefer the early style throttle body, so i put the 85-88 throttle cable in my 91. so you can use either throttle body, you just need the correct year cable that matches the year or the TB.

 

Since I've seen replies above about "progressive throttle rate"...anyone care to explain/show the differences that you are referring too?

PS...throttle bodies might work and interchange, but you'll have an issue or two...just looks for the differences when you hold either (plenum and TB) from 89-92 and from 85-'88, differences are obvious.

 

unsure of the cable thing, but the IAC passages are different on the 85-88 and 89-92 throttle bodies, from what I've been told the older style TB's will work on either but the newer style ones only work on the 89+ plenium.

 

good link will show all the differences.... http://www.hotrodlane.cc/PDFFILES/TPIStory.pdf

 

On the earlier style throttle bodies, when you barely applied the throttle it seemed like there was a little or alot. The progressive rate made it a smoother transition through the power range. I am not sure if this makes it more clear or not. Can anyone explain further?

 

www.thirdgen.org/1989-chevy-camaro

 

Thanks