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Dropping to 3.73s from 4.10s

Paul a buddy of mine might still have a 91 3/4 ton Suburban in N.CA. It was side swiped and is a parts rig. It has the 4L80E for sure cause I crawled under it and also ran the codes. I can give him a call and see if he still has it. I could probably talk him out of it for a few hundred if he still has it........
 
Well now..........

It's nice to know being a part of the original Brotherhood still means something. :woot:

You have no Godam idea how long this took me to type. :rotfls: :rotfl:
 
Correct me if I'm wrong, but did someone get into the Anti-Freeze last night? :D

Too bad the front's not a 10 bolt or you'd have a buyer for those gears. I'm at 3.73 w/ 285's and a small block As noted, they kinda suck. 4.10's would put me at decent engine rpm's w/o having to go 75-80 MPH to do it.
 
Hokay I'll go out on a thin branch hear and see if I get dumped off. What about a well built 700R4? Seems like it would eliminate all the computer issues and limit the adaptor issues - just get factory 454 bell housing for it. My last R/P swap was $550 in parts plus $300 in labor (I don't do diffs that las more then 10K) plus the cost of the spedo recalibration.

Just a thought...
 
My the 454 in my 88R20 burb gets real unhappy for any extended time above 2600 RPM. Its stock 454, TH 400, 3.73in the ff14, 265 75 R16e (almost 32 tall tires). Temperatures just go through the roof if you push it beyond those RPMs at steady cruise!

I have temp senders in the tranny and sump. Running down the hwy at 65mph even with 5K on the hitch its happy as a lark. Engine will be at about 205, Transmission around 180-190 and motor oil at 240. I start running around 70 (2900-3000rpm) The ening creeps up to 210, tranny matches it and the engine oil hits 325f real quick. My truck has the factory AUX electric fan and oil cooler and it does that. When you get off the hwy it takes forever for the temps to come back down. I am looking ar getting the cooler ot from in front of the radiator and ducting air to them. Also going to flip the tranny from radiator to cooler to cooler to radiator to drop the burden the tranny is putting on the main cooling system. Already has a brand new 4core and fan clutch and that didn't help.

The 454 is well out of its Torque range when you get near 3k. So I am in the same boat and looking at OD since I am getting run over on the Atlanta Autoban. Tires are about as tall as I am willing to go (its a street truck 2wd and now intention of cutting fenders on a truck with 86k on the clock. Besides its a tow rig and I need the E rated tires and E rated above what I got are ridiculously expensive.

I think the TH400 is still stronger the the 4L80 so I am leaning towards a Bowtie gear splitter OD. Then I might go up to 4.10's to make getting up to speed a little easier.

BTW: LTNS, How have you been? :D
 
The GV's ability to be used as a gear splitter gives it a big edge in actual towing performance compared to the 400/4L80. A built 400/ GV unit would be pretty much indestructable and having a 6-speed would be nice. However, a TH400 GV setup runs $2600+ last time I checked. A rebuilt 4L80 could be done for less than half that if you're resourseful. I would really like to have OD on my '80, even with 4.10's and 33's at 70mph~3000rpm I can't even stay with the flow of traffic most of the time. If I go the OD route, I'll probably swap a NV4500.
 
bowtiepower00 said:
The GV's ability to be used as a gear splitter gives it a big edge in actual towing performance compared to the 400/4L80. A built 400/ GV unit would be pretty much indestructable and having a 6-speed would be nice. However, a TH400 GV setup runs $2600+ last time I checked. A rebuilt 4L80 could be done for less than half that if you're resourceful. I would really like to have OD on my '80, even with 4.10's and 33's at 70mph~3000rpm I can't even stay with the flow of traffic most of the time. If I go the OD route, I'll probably swap a NV4500.
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The tranny might be that price but you also have to add in $600 for a stand alone computer to run the 4L80e AND the 4L80 may not drive the speedo (well on a 2wd anyway, 4wd you could get it to work)you may get into swapping a cluster. Or swapping the total FI, Cluster and harness to a 90-91 set up to run the 4L80. The only way it would be easier to do it is lucking out finding a rotted out 454 burb or Crew that had one already. Then you still don't get the 6 forward speeds with the gear splitter and the 4L80e is still not as strong as a TH400....close but not as.

Forget a TH700 NO WAY IN HELL it could handle a stock 454 towing anysort of load. GM knew that and that's why it never was an option.
 
W7NB said:
Hokay I'll go out on a thin branch hear and see if I get dumped off. What about a well built 700R4?
Click to expand...
The previous owner of my 1 ton had that bright idea too... now the tranny is nothing but a pile of scrap metal :haha:
 
Grim-Reaper said:
and the 4L80e is still not as strong as a TH400....close but not as.

Forget a TH700 NO WAY IN HELL it could handle a stock 454 towing anysort of load. GM knew that and that's why it never was an option.
Click to expand...

What makes you think a TH400 is stronger than an 80? They are identical besides electronics and an OD gear.

I somewhat disagree on the TH700R4. You need a built up unit. My 406ci small block makes a lot more torque than a stock 454 and I have towed a bunch with my K5, even up to 8K.

Where I do agree, I wouldn't have a healthy 454, any 700R4, and max out a 3+3 dually's GVWR very often.



CanCan....COME ON MAN! You drive 1K a YEAR! You'd save enough in fuel with 3.73's to buy yourself a beer (not plural).

It's a 454, I've got three of the darned things. It doesn't matter what you do.... drop one out the back of an airplane with nothing but the radio on and it's still only going to get 10mpg.:wink1:
 
Okee-dokee, Dug.

I'll assemble all the parts I need and come down and put it all together, with your help and expert guidance, in your fancy-schmancy new garage. How does that sound??? :rotfl: :rotfl:
 
Grimy....wow...is that really you? We are not worthy...lol.

Can Can....the gear swap is not worth the coin...especially in your neck of the woods...

The 4L80E is the way to go...or the gear vendors unit...both will require drive shaft work...
Look up azblazor...mark stopped by the house here in colorado years back and had supper with us....his k5 was a 454-4L80E-NP205 set-up and i can't remember the mileage he was pulling down but it was more then 12mpg.

And i'm thinkin due to the cost on the cancan...we might finger a way to get it to the K5 Garage in western colorado for the work as from experience your parts prices are double that of mine down here....and since she sits in the winter time in BC anyways....there's more then one way to skin a cat.

I've got an 91 R20 burb ecm and harness...i'll try and get to the boneyard after xmas and see if the trans is still there...all i have to do is sit down and compare notes between the 4L80E- Non 4L80E harness and wire it into your to make it stock....i think the adapter will be the biggest headache...

DW
 
Parts will have to be assembled from down here...way to damn much money up there unless some one gives you a wrecked 91 V3500 and you manage to find a place to store it...lol.

Well...this overgrown elf has toys to assemble before i can go to bed....will chat at you later and dependingt on ewhat you want to do we'll finger it out...

DW
 
Get your Christmas work done and then hit the sack, ya' big lug. Thanks for taking the time to come up with a plan for my truck without even being asked. The AZ and CO guys are right- you are a king among men....:bow: :bow: :bow:

Now I'm gonna go to bed with visions of 4l80s dancing in my head. How appropriate given the day.....:rotfl: :rotfl: :rotfl:
 
The 80e stuff can be found at significant savings here on CK5 and elsewhere (Craigslist, etc.), or in yards. If you are looking at purchasing the stuff new, then I'd go the GV route since they'll end up costing about the same. If you can find the 4L80 stuff for less, then grab it, rebuild it once and do it right, and never worry about it again. I think a built 700 would hold up fine in a rig that sees occasional light towing, but most one tons see more than that, and besides, who wants to worry about their rig breaking? 454/ 4L80/ 4.10's is a stump pulling setup.
 
Thanks for the feedback, brother. I'd REALLY like to find an affordable used GV unit somewhere, but the 4L80e looks like a more realistic options. Regardless, it seems that I'm gonna have no choice but to drive down to CO and let Dug take care of things for me.........:rotfl:
 
It's a different application, but 454SS.com has some good debate over 4L80e vs GV behind a 454. The 90 models came with the TH375 and 3.73's, while the later models came with the 80e and 4.10's. Lots of guys have gone both ways, and some even run built 700's with success- not much towing in that crowd though.
 
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