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**PCGUY112887** · 10-21-2009, 08:28 AM

I believe the 99 Transmission would have electronically controlled transmission line pressure, where as the 96 has vacuum controlled line pressure so unless someone knows different I don't think it would be a direct swap.

**IsaacHayes** · 10-21-2009, 11:53 AM

It should work. All 4T60-E were vacuum controled line pressure. I'm looking at the same year for my beretta... The century has the structural side pan too which is what I need to mount in an L body... Not sure what W body uses, but worst case is you swap side pans.........

**pocket-rocket** · 10-21-2009, 01:27 PM

I know the older ones were just regular pans, not structural. Not sure on the newer ones...

**gpse3400** · 10-21-2009, 07:44 PM

Side pans should be the same, structural. The only thing that could be differnt would be the final drive and the torque converter, which in doubt you could just swap over your old one.

**robertisaar** · 10-21-2009, 08:13 PM

your GP has a 3.33 final drive with a 2095RPM stall convertor

the 99 Century has a 3.29 "fine pitch" final drive and an unknown convertor...

**IsaacHayes** · 10-21-2009, 08:17 PM

Correct, FDR and stall could be different. That's part of my upgrade since my stuff is 1600 stall and 2.97 FDR.

**nutdpl** · 10-22-2009, 05:58 PM

Well what would be the best car to pull one from then? my local yard has tons of 4t60e's last i checked..

**3400-95-Modified** · 10-27-2009, 10:38 AM

99 Century's are 2095 FD converters, I know since I've done 3 of them lately.

99 Century's also do NOT have the L-body structural side cover... That is the easiest swap to do anyways. I think they have the proper W-body one though.

I just did one this summer in a day with Ryan Newnann over on the Bstuff board. His refused to shift properly so we pulled the stock 4t60e and dropped in a 99 Century one with the 2095 converter and the 3.29 diff, but I swapped the side cover and also swapped out the tone ring on the diff so his speedo was correct. Since he had a 95 ECM and car the shift points were un-affected since they are done by RPM only... Its 96+ that if you play games with the Final drive ratio then you may get some codes.

Isaac Remember as well that the L-Body needs the 6 bolt structural side cover, not the 4 bolt one, so if you found that the 99 has the 4 bolt (true) its not enough to bolt on our motor mount.

**IsaacHayes** · 10-27-2009, 01:13 PM

Yeah that's right 2095. L body is 1650 or something.

Good to know on the side cover. When doing the TransGo valve body "fix" do they supply you with new side pan gaskets or is this something that can be re-used?

How many teeth are on the tone ring? I can adjust the road speed constant so that's a non issue. BTW, OBD1 $DF shifts by both MPH and RPM. RPM has to be a backup fail safe. I'm betting OBD1.5 is the same. So going to lower FDR the MPH WOT shift point is never met, but the RPM one trips first and then it shifts.

**Azrael** · 10-27-2009, 11:57 PM

I wouldn't go as high as 2095 stall with the 3.33 gearing for a daily driver. I started with 1650 stall/2.93fdr and went to 2095/3.29 and I find it feels way too lazy under part throttle. I'm tempted to go to an 1840 or whatever the middle one is. Or I just need to find a way to throw more low-end torque at it...

**robertisaar** · 10-28-2009, 12:04 AM

thats what came standard on the 95 W 3100... and i'll admit, unless you're on the throttle, it feels tired. then around 3K, the VTEC kicks in.....yo.

**3400-95-Modified** · 10-28-2009, 08:47 AM

Originally posted by IsaacHayes View Post

Yeah that's right 2095. L body is 1650 or something.

Good to know on the side cover. When doing the TransGo valve body "fix" do they supply you with new side pan gaskets or is this something that can be re-used?

How many teeth are on the tone ring? I can adjust the road speed constant so that's a non issue. BTW, OBD1 $DF shifts by both MPH and RPM. RPM has to be a backup fail safe. I'm betting OBD1.5 is the same. So going to lower FDR the MPH WOT shift point is never met, but the RPM one trips first and then it shifts.

29 vs 30 and its not a fail safe if it works like OBDII, its a double meet standard, it has to meet both conditions before a shift will happen... Trust me, I've done it on OBDI.5 and it works fine, as soon as I went OBDII I was hitting the limiter, Maybe 1.5 its zero'd out... I've seen that done before. Either way it went by RPM not MPH in my case, and when swapped it to OBDII it got mad because the RPM didn't look right for the gear it was in and said my trans was slipping.

I know you say you can adjust the road speed constant, and so can I, But for OBDI.5 people its easier to swap the tone ring, but I can adjust it and it makes a change to the car I'm driving... Does your OBDI $DF run your car yet? :P

**IsaacHayes** · 10-28-2009, 01:09 PM

My 3100 when stock felt like VTAK kicking in at 3 grand too. That's just when the intakes/etc start working the best. But I do like the throttle response of the 1650. Maybe I'll buy a new 1650 and just go with that. I'm not sure the trans I'm getting comes with a TC anyway. That will be less heat, more response and economy. The 3.29 FDR of the buick trans will be the main increase of off the line punch. The factory stall is good enough to get the L body moving and with a better FDR and more powerful motor it should not be a problem. Hell my actual stall is way higher than 1650 with just the 3100. I think with all the issues Jon had with his higher stalls stalling way too high I'll just go stock. Thanks for the input guys.

I'll find out with the RPM vs MPH with OBD1 and experiment around and see if it's a both conditions must be true or if they are both there just as a fail safe. If it's the later then swapping to a higher FDR would still shift ok because the MPH wouldn't ever hit before the RPM, but the RPM point would tell it to shift then...

Quit busting my balls!!! I only have one car to drive to work and today is the first day that it hasn't been raining like mad. It doesn't help I don't get off work at a normal time either. Tonight I'm going to pull the glove box out and see if I can make a bracket to put the new PCM in the same place as the original. Then I can measure and start cutting wires and solder up the harness. And NO don't tell me to test it first then later tear the harness back apart and add wire length or remove length after I'm ready to mount it!!! LOL If I can't mount it somehow where the stock one is, then I'll measure and add length to route it somewhere else.... I'm only soldering those 60-100 pins ONCE!! That reminds me I'm out of heatshrink... haha

**asylummotorsports** · 10-28-2009, 01:21 PM

I have the FD (2095) in my 3t40 and it will stall as high as ~2300 RPM behind my 3500.

It's a little lazy on the street but gets up there pretty quickly with the 3:73's.

Needs a good cooler though, although all increased performance applications should have an auxilary cooler.

Jon what is that one you tried and gave up on. Still got it?

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96 GP, Use a newer 4t60e?

96 GP, Use a newer 4t60e?

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