HI range can be hard on parts.... but with the 205 case.. 3rd low is not much different than 2nd HI...
Bryan

 

1st is close to 4.5:1, 2nd 3:1, 3rd 2:1 and 4th 1:1+ little converter slip in all gears ( not a lock up TC). I have to do a little valve body work to make the shifts a little faster from 1-2 and 3-2 so I can down shift at the end and wonce i have it getting full rpm i may be able to shift to 4th at about 200ft. Now when I get to the end of the track I have to leve it in 3rd and it is just stalling out but you can see the nose drop about 6" when I let off so it wants to go so if I can down shift to 2nd it should pull mayby10-20feet more. The tc is so tight that it will idle up on the trailer in 2nd low and I have to hold the brake to slow it down. I use a devorced 205 with 32spline input and out put f & r with 1410 U-joints all the way around on the 205 and Dana 60 and Dana 70-U. 35-spline shafts in the rear, stock 35 spline inner and 30 or 32 spline outers in front. 3.45 gears but have a set of axles with 4.10's ready to go in if needed. Also have a dana 80 with 4.10's if a 70 HD dosent hold up but the 70-U has done fine for 7 years of 33" to 38" tires lots of towing and power (well not the power you guys have). I may take the Ally out and go back to a NV4500 to meet the rules and make it a DD again. Plan to use a set of HUMVEE 2 pice rimms I have and goodyear wrangler MT's ( 37x12.50x16.5 $125 each new or almost new at surpluss place) to drive and have fun and the BFG AT's to pull

 

The 545 fit under the floor ok? How much do those things suck up 50-75hp

 

I had to use a 3" body lift to clear the new #3 SAE flywheel housing but if not for it being 5" deep ( stock is about 1 1/2") it would have worked with out it. I think you would be suprised at how much gets to the ground. I dont think I am loosing much if any. His thing is not like any automotive auto trans. heres a link to a vid with 38x15.50 starting in 2nd then going to 3rd and 4th in high range. <object width="425" height="355"><param name="movie" value="http://www.youtube.com/v/PHCsiQqdz9I&rel=1"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/PHCsiQqdz9I&rel=1" type="application/x-shockwave-flash" wmode="transparent" width="425" height="355"></embed></object> and one more time <object width="425" height="355"><param name="movie I love to hear the straight cut gears in the allison wine.

 

I know that is a big tranny in a pickup, I have put a few in buses. Are you runnin 3.55's.

 

Yes 3.54's

 

Yes.....

2nd 4hi and 3rd 4lo, 3.54's

Tank, we spoke about the DD swap this spring right?

 

I dont know if I have talked to you before about it? It works great, everyone said they did not even make one for a getrag. I pull in 2nd hi with 4.10 and 35's.

 

The guy I spoke to in your neck of the woods was running a NV4500 with the big input, Like I am. Sorry for the mix up.

 

what neck of the woods? I am also building a motor and am going for 500 hp 14mm head, big inj, big turbo.