Does anyone know if a GM 8L90 transmission will fit in the tranny well of a 1996 GM B Body (Buick Roadmaster Limited) Without any body modifications?

 

No reply since 12 May 2016; I'll take that as a NO! Today is 31 Jan 2018

 

GM says its the same size as the 6L80.

 

Roger that Jimbo! Nothing like having the 8L90 setting in a shipping crate in my back yard. As a former tool and die designer, I get to measure all the numbers I need to check the clearances. Problem. It's 15 degrees outside and my pole barn is full of possessions. (Some call Junk) My swap mechanic does not want me to do the tunnel modification. We are off to a slow start but I'm next in line. This will be interesting.

 

8l90 is slightly bigger

 

 

The last pic the 8l90 looks huge compared to the 6l80e but that is because it is on a table that is higher. It is a little bit bigger in diameter and maybe 1 inch longer. Not much.

 

It's been three months now, my car is in the shop and problems have come from all four directions. We are getting closer to the last fitting so we can measure for the Drive shaft. I had to opt for a Dakota Digital instrument panel just to save wiring time. I'm about 10 grand over budget. And now i'm fighting the EPA regulations on Catalytic Convertors. The salvage yard has to sell the cats to legitimate rebuild shops. So while the engine will not run well with out the cats; the salvage yards cant sell the cats with the engine kit. So now you go to buy new cats and you are stuck with a core charge that you can't cover with the old part because the salvage yard took them off the engine. It is a racket that the EPA has created. I'm not happy as that adds $400 to the already very expensive four cats required on this engine. The hardest pill to swallow is the fact that we the people are paying these EPA parasites to cheat us this way.

 

What? If it's the rear cats you are talking about, they can be made null in the PCM tune. There are probably thousands of swap cars in Michigan that are running without cats.

 

No.......it will not.

KW

 

Summit has lots of cats where you will spend $200 to $350 for a pair.....I assume that your Roady will have 2 1/2" dual exhaust.....yes?

https://www.summitracing.com/search/...rder=Ascending

BTW.....$10000 OVER budget? Damn.....just, damn.

KW

 

just buy cats somewhere else ?

Bound to be hundreds if not thousands of places who could sell you them, whether new or used ?

 

Gen v swaps run fine without cats. We use a cheap aftermarket cat for compliance on the jeep wranglers. For cali compliance we buy a new gm exhaust system and cut it apart and for it to fit the jeeps. Its a pain and very expensive.

 

Tomorrow Nov 30 2018 will be one full year since I found and bought the LT-1 with an 8L90 tranny. At this point I would suggest that this is not the engine to drop into a B-body GM car. Had I the money to do it right I would have replaced the entire front frame and fabricated in a frame to allow the cradle mounted engine with rack and pinion steering and electric power assist.. But that was financially out of my reach. I have learned a lot about such a swap but still have lots to learn. I.E. the Camaro came with a 2:77:1 rear-end ratio.Its drive shaft was a two piece with a universal mid distant along the shaft and the slip joint is just aft of the middle pillow block and universal... I got some bad information on the weight of the 2016 Camaro. It is only 3,650 pounds or there about making it close to 600 pounds lighter than the 96 Roadmaster. I will reweigh the Roadmaster when it is assembled completely. I still expect the 0 to 60 times in the low 4 seconds. The 2016 Camaro 8 speed automatic boasts 3.8.seconds 0 to 60. Oh! K W; I know some local racers the know of the Livernois Motorsports shop but I don't want to drive that far. I'm going to exhaust the local talent before I go that route, but I don't want to drive that far. They will have to be a last ditch option when the locals can't do the job. Chevy stores will not touch anything that is not OEM. I'm working with my third tuning guy. The car goes on the Chassis dyno next Monday. I think the I think the Dakota Digital instrument cluster does not talk to the ECM and TCM as we have already confirmed that the original installation programing was set up correctly; that is the problem the tuners are working on. But the old muscle car motor mounts to not absorb the vibration of the AFM V-4 vibration; and I need the AFM system as the lady drinks champagne now. Right now I am at 15 K budget times 2.7 and climbing. Could have bought a new Traverse, but I don't want a new Traverse. The 96 Roadmaster fits my body.

 

Should have done a LSA and 4L80e and called it a day...

Andrew

 

Yeah! So soon old and so late smart. But I like 8 speed tranny and when the shift point get resolved it is going to be a fun car to drive. It pulls a popup camper like there is nothing back there.

 

how about some pics

i'm not sure what all was included in the cost to do your swap but the numbers you posted seem excessive

why? that's like saying should have gone sbc th400 to the first guys who jumped in to ls swaps

 

Yeah, everyone that has looked at this car after the installation of the engine has said I spent too much. I have to admit I feel the same way but when your half way there and the money is gone and the job is not done; Well, I had to sell some stock. Being retired sucks and this engine and tranny combination is not a shade tree mechanics work piece. Adding insult to injury; my first trip to the chassis dyno did not get the results I had expected, but I can't blame the HP tuner as I did not know exactly how to communicate my wants. I just assumed that he would make it ready for the drag strip. The ECM was shipped to Kokomo for the VATS flash and that made the ECM dumber than a box of rocks. I.E. the rev limiter was set at 4800 rpm; Why that did not throw a flag to the tuner is beyond my understanding. But that is the way it is and I need to schedule a second trip to the tuner. Apparently the new cars of all makes have to have a very strong battery due to all the computer demand. Quote and end Quote. My experience is; anything below 11.7 volts and the engine will roll over via the starter but it will not fire. It sounds like that is not anything that can be set in the ECM so I'm springing for a yellow top Optimum battery, and so the cost factor goes up again. But I think this is the very first B- Body GM car that has 2016 5th generation LT-1 engine in it. Still a lot of miscellaneous things to finish off the drivability of the car but I can do that on the days that I have no where to go. It helps to be retired. Right now I enjoy staying a car length away from the Camaro ahead of me that has the special license Plate that says JUSTGON.. Not any more your not! Wait till I get all 455 horses pulling for me. And for all who said I should have stuck with the 4L60E; The 8L90 has a 4.5:1 1st gear ratio. This 22 year old car comes out of the hole like a bat from you know where!

 

Just got my car back from the HP Tuning programmer and it has received a full GM 2016 Camaro LT-1 profile, minus the VATS. It still will not rev past 4800 RPM under full throttle without going into rev-limiter mode. Half throttle works fine. What am I doing wrong.? This is new ground for a lot of builders. I don't know of any one else that has put a 5th generation LT-1 into a 1996 B-body GM chassis coupled with an 8L90 transmission. Any suggestions on where to get answers, Some sensor is not giving correct data the ECM and or TCM.or both. The local GM dealer will not touch this car as it is not OEM.

 

Then diagnose it, same as you would any car.

fault codes, view live sensor data to see which one isnt making sense.