YenkoST

iTrader: (5)

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.

YenkoST

iTrader: (5)

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

92blue

iTrader: (1)

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.

YenkoST

iTrader: (5)

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

S10Wildside

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.

8Mike9

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.

S10Wildside

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.

S10Wildside

Here's an 85-88 plenum.

YenkoST

iTrader: (5)

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?

8Mike9

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

Good info.