Hey guys,
I have a chance to get a 58mm TB for my truck that I switch to TPI on but it is for a 85-88 year model maf camaro but I set my truck up as a 1992 Speed Density camaro. What is the difference in the two throttle bodies? Will it work? Thanks for the help.

 

Just talked to Holley tech and he said there is no difference in the two throttle bodies. Answered my own question.

 

The Holley tech doesn't know what hes talking about. The difference isn't a clear cut MAF vs SD thing. Its between 85-88, and 89-92 (89 was MAF while 90-92 was SD).

What year is your plenum? The 85-88 TB will work fine if your plenum is an 85-88 model. It its 89 or later, the 85-88 throttle body will not work well because it lacks the IAC hole in the plenum.

By the way, the throttle cable also changed between the two years.

 

I have the StealthRam on my truck and use the camaro throttle cable for it.

 

Doesn't the 1989 plenum have an IAC hole? It's the only TPI plenum with a perfectly round hole. The 85-88 plenums have a triangular shape hole (sorta). The 90-92 plenums have no hole at all.

 

I think the only difference between '89 and '90-'92 is a MAP connection fitting...I don't recall if my '89 had a hole in it or not?...but I don't think it did.

 

No, the 89 plenum has a small hole in front. The 90-92 plenum has no holes...other than the main two.

Here's an 89 plenum I recently cleaned. I also have a 91 plenum that only has the two large holes.

 

Here's an 85-88 plenum.

 

the Holley Tech guy said that the 58mm throttle body #112-503 comes with the StealthRam system and it can be used for any setup. So will it work with my stealthram on a 1992 setup?

 

That's odd, since 89 uses the same TB...but it's pretty obvious with your pics posted.

Good info.