Thread: 01 L67 in 97 GTP Chassis - Need Vacuum line help

You can follow either of the two routing systems.

In 97 the tree by the TB fed the boost control soleniod and the fuel pressure regulator.

In 98+ the tree was not there. So a T came off the LIM to the FPR and BCS. Making the vacuum a basic horseshoe.

So the first diagram wouldn't be correct at all then, right?....there should not be a vacuum line off that tree to the tranny at all then eh?

The first diagram IMO is totally whacked because it says 97 GTP. All 97 GTP's should (key word as 97 might have had one or two 4T60's) have only had a 4T65 trans in the GTP or Supercharged model. The 4T65 trans is fully electronic and doesn't need vacuum for anything. The 4T60 aka predecessor trans used vacuum.

so no.. no vacuum to the trans.

i was pretty sure the first diagram i posted was wrong but the ppl on this site really know their stuff....thot id ask to be safe.

any idea if i need to use the 97 blower (with the tree on it) in the 97 gtp chassis or if the blower off the 01 will work?...what im trying to say is if i run my vacuum lines on my 97 like my 00 gtp is set up, will it work or do i need that tree and and follow diagram #2?

You can use either blower and either vacuum setup.

If you use the 97 blower and want to use the 00 vacuum you simply cap those tree ports. Or you can hook it up like the second diagram.

If you use the 00 blower then you use the horseshoe vac line setup.

It's really up to you. Personally I like the 00 vac line setup better because GM made each nipple a different size from the other end and that's a pain to connect new lines to at times.

ok....so i can use either vacuum setup...sweet (makes it easier to run the vacuum lines when my 97 n 00 r side by side)

I appreciate all the help too Bill...

Now what about throttle bodies? can i use the 98+ or must it be the 97 tb?
and is the wiring harness in my 97 gtp different than my 00 gtp?...is it a plug and play system to drop a 98+ engine n tranny in the 97 chassis or does the 97 chassis have more electrical components to operate the engine properly?

I would say run the 00 TB. It has a better amount of air gobbling abilities and the maf tables aren't much different from 97-00. Ideally you'd have someone with a DHP put the table into your pcm. But you'll never notice the different otherwise.