Bowtiered

Why does the auto haev 590ft lbs in the 6.6 as opposed to 520 with the 6spd? what are the differences in the engine? or is it just one of those chevy rating things where they rate one higher because they want it to be more appealing and there aren't any differences (eg. SS vs Z28)

Hit Man X

70ftlbs is a big different, not gimmicky.

My best guess is due to the OE clutch or flywheel not being able to take the abuse. You can easily up the power via a fuel+timing box (when they come available) but watch the clutch slippage. The ZF 6 speed is a badass tranny and I don't see it breaking...it's just what's mounted infront of it I'd be concerned with.

Any reasons you aren't interested in the Allison?

Bowtiered

Yes. I like manual transmissions. Never been a fan of autos behind diesels, even though the new ones are getting better, just not a fan. i like shifting my own gears as well. i'm not going to buy a duramax, i'm buying a 99 4x4 RCLB 7.3 6spd superduty. mainly because of the SFA. I know the D50 has got to go once i start lifting it- i'll probably be going 10 or 12" with 39.5" boggers. But firstly it'll be dual smokestacks with the Edge kit, propane, and maybe a new turbo housing. I'm wanting later on to get around 1000rwtq with nitrous, but i'll stick to things that are run constantly as opposed to shrt bursts first, until i need nitrous in the mud. i want a duramax later on, once i have enough money for an SAS- which i'll do myself so it won't be too extravagant price wise, but i don't want to pay up for springs, brackets, driveshaft, panhard rods, 35spline outers etc. quite yet.

Hit Man X

Well the 4R100 Ford 4 speed auto (well until they came with this new 5 speed) is totally different than the Allison 1000. Kinda the wrong place to be askin about the Powerstroke (granted I HIGHLY considered before choosin the D-max I'm gonna order and I know a fair amount about them) seems off base comparin the GM vs Ford 6 speeds...tho' I think they are both by ZF.

Just remember you're gonna drop boost between shifts with that setup. And a well build auto will run that long throw 6 speed right off the road in terms of acceleration.

To me it'd be foolish to buy a truck you're gonna drop all that cash into then toss it for a Dmax later. If you're really going to toss that Dana front axle on the Ford there's no point going that route if you're gonna do the same thing on the GM truck. There are billet tierods out now for that IFS and I could have sworn I saw some bigger CVs too.

Go surf the Ford diesel sites, I haven't seen any lay down that much power with a single turbo and the 7.3L, most step up to the Cummins powerplants in those trucks to get that sort of power. You basically really need to sit down and think about what you're trying to achieve. I don't think you realize the amount of cash you're talkin about shelling out for programming, LP, N2O, turbo... Tranny Upgrades, U-joints, Injectors, Tie rods...

There's a lot more there you need to consider.

Snake Eater

Chevys factory power ratings are NOT taken from the flywheel. They are taken from the output shaft of the trans. Most people dont know that. Thats why F-bodys rated at 305hp pull 295-305rwhp bone stock in a M6.

Dodge may also be rating there power at the flywheel, which is why the Hemi's dyno in the 250s stock with there "345 hp hemi" VS. say my 5.3 "285 hp vortec" which dynoed 259.6 stock. Most stock 5.3s i believe dyno in the high 240s-low 250s.

Hope this helped somewhat.

LOW2000

When I dynod my 04 trailblazer 5.3 last week with only 500 miles it made 230hp if that helps anything, its rated at 290.

Bowtiered

Ok- ditching the D50 for a D60 is much less money than ditching IFS for SFA. The reason i want SFA is not necessarily strength. it's flex, and fewer moving parts. I don't want IFS in a lifted truck. I'm also not going to ditch the ford, i'll keep it and also have the dmax. AFA ujoints are concerned, that's $60 per joint ONCE with CTM joints. i just don't want an automatic, it's not that they are bad, i just don't want one, that's all. I like shifting my own gears. also i cannot find a single duramax in my price range (initial investment) i don't want billet tierods and bigger CVs, those would be the least of my worries, until it got lifted. and without dropping the whole suspension on an IFS truck the CVs, no matter how strong are going to break. a D50 IS actually a D44 ring/pinion with D60 shafts- which really does no good because the spiders are the weak point in D44s. also rack and pinion steering is just not meant for big trucks, hi steer cross over with hydro assist is, and there are MANY kits for D60s.

Basically, you and I are going for two different things- i want a lot of power, a BIG drivetrain and a manual transmission. you want an auto and TONS of power. i would rather have a duramax ENGINE, and maybe i'd swap in a duramax or cummins 12v (cheaper aftermarket) into the ford later, but i'm not really wanting to do an SAS anytime soon.