finally got my TBI today, and i've been noticing the differences with that of the 454 and my stock 5.7.

looking at the front of a TBI you see 3 places for your emissions hoses/plugs. My stock TB has one of the LEFT side and the two in the middle... this 454 TB has the left blocked off and has a slightly smaller hose fitting on the RIGHT side. it is labled with an 'S' stamped under it, while my stock TB has no label. (i know this sounds confusing i could provide a photo if need be)

does anybody know if its merely switched sides/hose size, or is it for a different line all together?

also the darn wire plug doesn't match up... any GM mechanic can splice in a new one, right? (i know there is a post about this somewhere...)

another thing... do you think my truck will be drivable untill i get a new chip programmed? off the line it might ping... but who knows what that extra air-flow will do to the computer.

thanks guys

 

The red circle is where the stock 5.7 has its hose connection, which is slightly bigger vs. the 454's connection on the right. (blue circle)
So is this the same connector... or should i not plug in things that might not belong? seems like it all dumps into the TB anyways... but i'm not exactly sure when it comes to emission hoses.

the ones circled in green are the same on both TBI's...

 

Every one of those are just vaccum lines. Cut, splice, plug, and "T" in where needed, just get all your olf lines connected again.

About the wire plugs (TPS, and IAC) just go to any wreckers, the 454 tbi uses the same plugs as most gm cars (88-93). The wires on the new plugs will be the exact same color, so just cut the old plug off. If they charge you more than $5 for the pair, there ripping you off.

You won't need any tuning if you run you 350 injectors, Ideally you would want to raise the fuel pressure a couple pounds to match the increased air flow. 454 injectors will cause you to run way to rich.

 

Can anyone tell me what order the wires go in from left to right on the IAC valve for the 454 tbi, I have a connector that wil work but its not color coded correctly.

 

It should be labled A-B-C-D... here is a link to a past post which should help a lot.... it guided me through it quite well.

https://www.thirdgen.org/techbb2/sho...hreadid=188744