Another 1991 Suburban
- Thread starter sean257
- Start date
Haha, thanks! Yes, I did get thick cut, and it made me feel like I was buying steak.
I do not know if I have a tv cable issue, a tired 350, or a weight issue. A Google search makes me think that the stock curb weight would be more in the neighborhood of 5500-6000lbs vs my 6500 lbs.
I do not know if I have a tv cable issue, a tired 350, or a weight issue. A Google search makes me think that the stock curb weight would be more in the neighborhood of 5500-6000lbs vs my 6500 lbs.
Larry
Bigassgas Explorer
I agree, 5:13’s are going to be wayyy tooo deep. 5:13’s will be regretted one day
PMA4x4
Adventurer
If you are running 35s' right now with 4.56s. then you are at the "stock" rpm/speed range. granted you have a few hundred pounds of bumpers and what not but either way it should not be "hunting" between 4th and 3rd. You say this is all happening at 70 up hill? try slowing down a bit.
your 4th is actually the OD. driving down a level you should hear essentially 4 shifts 3 normal and the 4th one is light and will only drop down a couple hundred RPMs. thats the Lockup in your torque converter that's what helps give the MPG and keeps the tranny running cool. It's normal for it to pop out of Lock up (LU) into regular OD or even 3rd.
on my truck right now I just manually shift it into 3rd and leave it till i am over the hill. it will go into lock up when in 3rd as well.
If it keeps hunting I think you are cruising at a speed that is just between gears so its not sure what to do. Its the same concept as regearing. 4.56 not enough 5.13 too much so maybe 4.88 will work. Its the same just in the tranny.
700R4s are a very touchy tranny when it comes to the TV cable adjustment.they can burn up quick of adjusted wrong."
Check this link out. Great info in regards to TV adjustment and how it works
http://www.tvmadeez.com/article/
If you already knew this then disregard.
your 4th is actually the OD. driving down a level you should hear essentially 4 shifts 3 normal and the 4th one is light and will only drop down a couple hundred RPMs. thats the Lockup in your torque converter that's what helps give the MPG and keeps the tranny running cool. It's normal for it to pop out of Lock up (LU) into regular OD or even 3rd.
on my truck right now I just manually shift it into 3rd and leave it till i am over the hill. it will go into lock up when in 3rd as well.
If it keeps hunting I think you are cruising at a speed that is just between gears so its not sure what to do. Its the same concept as regearing. 4.56 not enough 5.13 too much so maybe 4.88 will work. Its the same just in the tranny.
700R4s are a very touchy tranny when it comes to the TV cable adjustment.they can burn up quick of adjusted wrong."
Check this link out. Great info in regards to TV adjustment and how it works
http://www.tvmadeez.com/article/
If you already knew this then disregard.
PMA4x4
Adventurer
As for more hp/tq there are a lot of options being you have all that engine bay to work with. You can easily just do a cam, headers and intake swaps but then kiss any MPG you have goodbye. Most are doing new motorswaps to gain in MPG (or at least keep what they have) and gaining in power.
I think Larry is doing a 5.3LS or a 8.something swap (Correct me if I am wrong larry).
Me... I am still up in the air. A this time I am considering a a full roller 1998-2000 5.7 Vortec. which is drop in for me. its the best results with budget in mind.
Others have done and even I considered for a while a Cummins 12 valve diesel swap but realistically when you add it all together you are talking about roughly a $8,000 swap.
You could do a 454 swap. that's all bolt in but that would require a different tranny and maybe different length drive shafts depending on position of T-case
Dont forget with all this is you want to keep fuel injection then you have all the wiring and PCMs along with it too.
I think Larry is doing a 5.3LS or a 8.something swap (Correct me if I am wrong larry).
Me... I am still up in the air. A this time I am considering a a full roller 1998-2000 5.7 Vortec. which is drop in for me. its the best results with budget in mind.
Others have done and even I considered for a while a Cummins 12 valve diesel swap but realistically when you add it all together you are talking about roughly a $8,000 swap.
You could do a 454 swap. that's all bolt in but that would require a different tranny and maybe different length drive shafts depending on position of T-case
Dont forget with all this is you want to keep fuel injection then you have all the wiring and PCMs along with it too.
onemanarmy
Explorer
this may have been covered...but why are your side steps so 'thick'? They look incredibly heavy.
Larry
Bigassgas Explorer
Actually, 8.1L. I am a big block gasoline kind of guy only. Small blocks are for dirt track racers :ylsmoke:. I installed an 8.1L in my K10 6 years ago and getting ready to swap one into my Suburban as well. My personal opinion is a small block, even a well built one, is barely adequate for a large truck like a Suburban especially as heavy as Sean’s is becoming with all of that metal he has glued on recently.
Many people hop up small blocks or swap in late model Gen III small block engines in these old rigs because they are cheap and pentyful but the reality the small blocks consume just as much fuel as a big block, if not even more, due to the small engines having to work to their gonads to death in order to propel the enormous vehicle. If you are going to get 10-12 MPG, you might as well have over 400 HP and over 500 lb. ft. of torque on tap to go along with the less than sterling fuel mileage, which is why the 8.1L is the engine of choice for me.
It is true decent horse power can be mined out of a small block but they will never come close to the low RPM torque of a big block. Low end torque is what propels these large trucks, not high RPM horse power like a small block delivers…especially a late model high revving Gen III. My 8,000 lb. K10 with the 8.1L gets 10-12 MPG while my much lighter TBI 5.7L Suburban gets 9 – 10 MPG and it can’t pull a greasy string out of a Coke bottle. Both trucks run the same tire size and transmissions. When pondering an engine swap on something large like a Suburban, a big block or a worthy diesel really should be considered into the build at some point.
A 454 would not require a transmission swap although the 700R4 will be short lived but could be built to easily handle big block power...of course, at at a cost. To run TBI on a 454 would not require a complete harness change although the ECM, PROM and some minor harness mods would need to be done. I just did a TBI 4.3L V6 to a TBI 454 in my FIL 1993 Sportside and just modified the 4.3L harness. It a straight forward swap. GM trucks are easy to build! :elkgrin:
Lots of options when it comes to building GM vehicles….
PMA4x4
Adventurer
Thanks Larry I could not remember which one you were doing/did. I do agree with pretty much everything said except that the transmission would have to be changed due to bellhousing sizes of SB to BB.
I would try and just do a full harness swap so nothing is highly modifes to the point you cant get a part for it at a local store. I have been exploring more and more on a late 90s BB to drop in. I currently pull 12.5 loaded so its not too bad.
As you can see Sean the ideas to get more power is really open to your imagination.... and your wallet:wings:
I would try and just do a full harness swap so nothing is highly modifes to the point you cant get a part for it at a local store. I have been exploring more and more on a late 90s BB to drop in. I currently pull 12.5 loaded so its not too bad.
As you can see Sean the ideas to get more power is really open to your imagination.... and your wallet:wings:
Thanks a lot for the feed back. Also, damn it Larry! I just decided a 6.0 might be ideal, due to price and ease of swap relative to 8.1. Tell me about the 8.1, because I was not able to find your build thread, and what I could ?find looked like pretty extensive frame mods and welding etc... Would a 6.0 be that bad compared to my stock 5.7 and relative to the work/expense of an 8.1?
Larry
Bigassgas Explorer
Negative, there is 00000.00 difference between the Chevrolet big block and small block bellhousings. Not sure where you got the notion they are different. In fact, there is zero difference between any Chevrolet straight 6 or V8 bellhousing from the past 70 some years. Essentially you could take a modern 6L90 6 speed auto and bolt it on the back of a 235 straight 6 from the 1940’s or even take a 1960’s Power Glide 2 speed automatic and bolt it behind a 2014 Duramax if you wish. That is the beauty of GM consistency and ease of powertrain swappage. Can't say that for Ford or Dodge
Depends on which engine he would go with. If a TBI 454, it is a no brainer to reuse the TBI 5.7L harness which would be no different than my recent 4.3L to 7.4L swap that only required slight wiring modifications of the OEM harness (Like less than an hours worth of work to modify). If he went the route of a Vortec 6.0 or 8.1L, I agree....a complete new harness from a supplier such as Howell Engine Development would be required. I don’t use any aftermarket components for my powertrain swaps. Even the harness to run the 8.1L in my 70's GM truck is made up of genuine GM/Delphi components so parts can be purchased anywhere on the fly. Including the fuel delivery system….no aftermarket parts.
A 6.0L probably would be fine at your altitude but if you are considering going through the motions of a modern powertrain swap why settle on a lesser engine (Gen III small block) when the big power engine (8.1L) can be found for the same money, is actually easier to install and gets the same if not better fuel economy in heavy rig. There is a member here and personal friend of mine that just bought an 2002 8.1L with 70K miles to swap into a 1995 2-door Tahoe for $1000.
Contrary to popular belief there are zero frame modifications to be done to install an 8.1L when using the proper accessory brackets and exhaust manifolds. If you Google 8.1L swap you will find a swap article from a WyoTech Instructor that installed an 8.1L in an 80’s GM crew cab. The guy did not research his swap very well or he would have discovered the frame did not need to be hacked up to make room for the A/C compressor and exhaust manifolds. Using GM Medium Duty Truck or G-Van accessory brackets allow the A/C compressor to mount up on top the engine opposed to the side of the engine where the frame interference occurs. He would have also discovered the 8.1L will accept any older BBC exhaust manifold or header. A set of 454 exhaust manifolds would have saved him from cutting the frame for exhaust clearance. Lastly, he would have discovered the firewall doesn’t need to be hackup either to make room for the EGR valve as the valve can be removed and the EGR function tuned out of the ECM as well as about 10 other things he wasted time and money doing. If you look at my swap pictures there are zero frame mods. I pulled a 7.4L out in the morning and stuffed the 8.1L in that same afternoon. The 8.1L is a straight drop in to the existing small block or big block mounts as well so no modifications there although there will be some oil pan clearance issues to deal with, which the ORD HD engine cross member can fix. You can’t say all of that for a Gen III small block. You will also play hell finding the proper exhaust manifold or header to fit a Gen III small block in an old truck without cutting the frame. In my opinion the 8.1L is a much easier swap than any Gen III 5.3L, 6.0L or 6.2L with much greater rewards.
I have gotten overwhelmed with PM’s and emails from various forums where people want to know how to go about an 8.1L swap. Given my worn-out enthusiasm to address every PM from people that just want to pick my brain to death without doing any research of their own I created this thread to help people with their 8.1L curiosities. Check it out :ylsmoke:
I don’t have a build thread on my 8.1L swap but I do have all of the pictures here. I think you will agree it is a sanitary swap with no
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PMA4x4
Adventurer
I am going to go with your answer. Its been so many years since I've been messing with GM I would not doubt I am getting info mixed up. I've been buried in Jeeps for the last 14 years. so there is a lot I need to try and drudge back up.
Maybe it was fords. Anyways there it is.