PontiacBonnevilleClub.com

Scouring craigslist last night I came across a 2001 100k L67 complete without trans for $200. No brainer gonna go buy it in a few hours.

My question is, will doing a top swap cause an issue for the vacuum controlled trans that is in the car (1997)? If it will, how do I get around it?

If you suggest swapping the engine out entirely, that is the plan eventually. But I want to just give her hell and not worry about breaking, since I will have the L67 short block.

Thanks

It's probably going to be easier to swap the whole engine. Not sure on the vac thing, but '96 has the L67 on the 4t60 so shouldn't be too much of an issue.

You shouldn't have any issues with it, you'll just need to make sure you route the vacuum line correctly. For tuning purposes and aftermarket though, the 4t65e is miles ahead of the 4t60e that came in these cars. If you have the chance to upgrade I would do it.
Just my $.02

Thanks for the replys. I just am unsure about the tranny vacuum because the 98+ have electronic controlled tranny so there are no provisions for it on the newer top end.

I know I should swap the motor and get a trans but I am impatient and don't have the money for everything so I'll take what I can get

Come to think of it, I'm not positive but I would think that the wiring harnesses between the two transmissions are different.
If that's the case you'll probably have to rewire your old harness to work with the l67 unless you get really lucky and find a 96 ssei in the junkyard that you can pull the wiring harness from. I'm sure someone else will have the details about that though. It's been a while since I've touched the 4t60e.

I'm not swapping the trans until I blow it up though so I don't think wiring will be an issue at this point. Hopefully not anyways. Getting ready to go tear her apart right now! Taking the heads to get port/polish before anything.

the modual will be fine with boost. I had a 4T60-E in my Turbo 3.4L LQ1 monte and no problem with it seeing boost. I will say tho it does like a OEM Factory Vac modulator.. had issues when the trans was built and a "Red Strip" aftermarket one was put in. It actually shifted very well with the boost going into the modulator. I tired running it like the 89-90 TGP's had it with a vac res and a check valve and i didnt want to shift correctly. put boost to the factory modulator and it was perfect.

S

bs009 wrote:Come to think of it, I'm not positive but I would think that the wiring harnesses between the two transmissions are different.
If that's the case you'll probably have to rewire your old harness to work with the l67 unless you get really lucky and find a 96 ssei in the junkyard that you can pull the wiring harness from. I'm sure someone else will have the details about that though. It's been a while since I've touched the 4t60e.

the harness for a 4T60 and 4T65 are different. so if you are going to go to a 65-E you should just start there or you will be swapping harnesses again later on with the transmission. I ran a 60-E with 331hp/350TQ for a long time before it let go. But then again a S/C L36 will make more TQ then a Turbo LQ1

redzmonte wrote:the modual will be fine with boost. I had a 4T60-E in my Turbo 3.4L LQ1 monte and no problem with it seeing boost. I will say tho it does like a OEM Factory Vac modulator.. had issues when the trans was built and a "Red Strip" aftermarket one was put in. It actually shifted very well with the boost going into the modulator. I tired running it like the 89-90 TGP's had it with a vac res and a check valve and i didnt want to shift correctly. put boost to the factory modulator and it was perfect.

S

Awesome that's what I was looking to hear. Didn't know if boost was going to make the trans do crazy things. Thanks

The trans vac modulator line comes off the throttle body before the rotor pack. So it won't see boost. If you use the 99 throttle body just drill a hole in the same location as your second vac fitting on your stock throttle body and put a barb on it.

Sup I'm new, but I can tell you I've already blown up a trans in my 94.

95naSTA wrote:The trans vac modulator line comes off the throttle body before the rotor pack. So it won't see boost. If you use the 99 throttle body just drill a hole in the same location as your second vac fitting on your stock throttle body and put a barb on it.

Oh ok great I was thinking vacuum would be wacky anywhere on the engine with boost, thanks

redzmonte wrote:the modual will be fine with boost. I had a 4T60-E in my Turbo 3.4L LQ1 monte and no problem with it seeing boost. I will say tho it does like a OEM Factory Vac modulator.. had issues when the trans was built and a "Red Strip" aftermarket one was put in. It actually shifted very well with the boost going into the modulator. I tired running it like the 89-90 TGP's had it with a vac res and a check valve and i didnt want to shift correctly. put boost to the factory modulator and it was perfect.

S

A turbo LQ1? I am intrigued, any pictures of the setup? In a different thread of course.