Allison on a Gasser

sleepur606 · December 17, 2006

All right, I know this has been answered before, and I know I've seen it somewhere, but I can't find it and figured I would get the least flack posting my question here.

1.) Is the bolt pattern on the bellhousing of an Allison 1000 transmission that is on the 8.1 Gas and 6.6 Duramax a standard small block Chevy pattern? I think I remembered hearing something like that and that as long as you can get a flexplate to bolt up, you're good to go?

2.) If all goes well and the Allison will bolt to the Vortec 6000/6.0 LQ4(?) that's in my 2002, how would I go about controlling it? Could I just connect the Allison TCU? Will it communicate with my stock ECU?

I only ask because a built Allison would have either 5 or 6 speeds depending, probably 5 knowing me, and it will hold more torque than a built 4L80E. Lastly, adding a Gear Vendors overdrive unit to a 4L80E makes the Allison a lot better budget wise. The project is going to be a supercharged 427/454 LSX based engine that should be making a few pounds of torque and I don't wanna go through the trouble of buying a trans just to balloon converters and break parts.

Thanks in advance.

ZZebes · December 17, 2006

Short answer, Cant be done.

The Bolt pattern for the allison is completely unique plus the Allison is by no means a performance transmission. It soaks up horses like a sponge. The allison has almost double the parasitic loss of the 4l80e

Haulin' 8.1 · December 17, 2006

The bolt pattern is standard Chevrolet. They are not casting HD blocks for Allisons and SUV blocks for 4L80E. I agree that it's not a good choice for performance. There is a stand alone controller availiable for the Allison though. I believe it's the ATS Co-pilot. I would go the 4L80E Gear Venders route.

Resons:

The gear spread is way wide. You'll need AWD to be able to launch and still use drive in the quarter.

The unit is very large and heavy, inside and out. Like he said sucks up a lot of power and performance.

Gear changes are done one at a time. If you're cruising in OD and floor it to pass you'll see 4th on your way to 3rd. It takes a while.

Parts and builds are very expensive yet they still slip them up all the time.

The Co-pilot isn't cheap.

Gasoline performance convertors would be a complete custom job, more $$$.

Fewer people are really qualified to do what you want to with an Allison. There's probably a 4L80E shop a lot closer to you that could make a 80 live.

If you do it good luck. Just saying I wouldn't, not that it's impossible.

Vernon

linda · December 17, 2006

I agree, my Allison is a rock...but it sucks up a lot of HP. I think in the long run it would take muck more time and money to make the Ally work with anything other than the 8.1L or the Dmax.

sleepur606 · December 18, 2006

Well thanks for all the info, I guess the 4L80E is the way to go then, just gotta make sure I find one that'll handle everything, I think Bowler Performance Transmissions could do it.

Thanks again