91 burb parts interchange and swaps advice

[Smogmonster]

hi all this is my first post and hopefully i can return then help.

1
i need some advice. i have a 91 burb 4x4 and i need to fix a leaky steering box
i also have a 78 c20 2x4 i was going to use or part out or sell
it has a recent steering box but can i make it work on my 91?

2.
i prefer the look of 70,s trucks front ends can i swap in the front bodywork from one to my 91? i may just get another earlier burb but i allready got a lot of work in mine

3.
i currently have a semi floating 14 rear axle with 410 ratio i would prefer something taller maybe 3.73 or 3.5 for highway use. my 78 c20 has a ff 14 with a recent locker and 3.73 ratio BUT is it easier to just swap in a complete axle
or swap in some gears from a parts truck? i realize my 91 is 4x4 so the front would also need doing and the same question applies.
i would use my 78 axle but i might sell the truck or the axle and imo its too heavy for my intended use.

4.
i have the factory inverted front stock 2 leaf springs that i think are in need of a boost
can i flip the main or both springs upside down to gain some lift? maybe add a rear leaf? which way up? its not that i want it in the air i just think theyre worn out or overloaded and i dont like the way it bottoms out sometimes allthough on the freeway it drives nice.

5.

i was offered some pro comp 13411 front 4 inch lift springs i could use as the truck is sagging anyway so i thought it may just add 2 inches? or maybe remove a leaf? i dont need or want it in the air too much or too stiff or to waste money and i am concerned it will be a dominoe effect and il also then need different steering or extra other parts ? $$$

i also have a spare good set of rear c20 hd springs i thought i could addapt but i think it gets a bit long winded to do that moving hangers etc? and just gives u flex which is useless for me for highway use

sorry for all the q,s but thats why im here

polite usefull replies welcome

thankyou

[andrewmp6]

For the first one the 2wd and 4x4 steering boxes are different,Only way to use a 2wd box is to do cross over steering which is not needed unless you have 4 to 6 inchs of lift.For number 2 i believe you have to change the whole front end from the firewall forward core support and all.I would rather swap the whole axle then just the gears from one to the other.And being a 4x4 you have to re gear the front axle to match the rears ratio.So if your going that far i would just buy new gears and have them installed if you don't know how to do it.Honestly i would just buy new 2 inch lift springs for the front and a rear shackle flip that will give you 2 and half inch lift in the rear.Look at http://offroaddesign.com/catalog/2inchliftsystem.htm

[Smogmonster]

hi Andrew thanks for taking the time to try and help.

so just thinking out loud here is it the pitman arm thats different? and wont swap over? or the threads so i would need the hoses etc ? maybe cut and weld the 2 pitman arms together to correct it????

its just that i allready have those parts and i may part out the 78 anyway.

so the front springs i allready have WILL they flip over? i dont really want to dump cash into it just too make a small lift (right now it only has about 1.5 of travel before the bump stops) but i have a lot of weight up front so i wondered if the 4 inch lift springs my buddy has could work and save some $$ i dont want it up in the air too much for lots of reasons.

[Ski-me]

No your front springs won't "flip". When you take the load off of them, you will get them to be flat. IF you want more lift, either find a factory 3 spring lift that's on heavy duty trucks/suburbans. A lot of 3/4 suburbans could have them. Or add a leaf in the pack.

With that said, the springs are probably worn out so getting new ones would be ideal. To level out the back, either add a leaf, install "zero rate" from ORD, or new springs.

You really aren't going to see much difference going from 4.10 to 3.73. I'd leave as-is. Far too expensive to "maybe" gain 1 mpg. Also, you will lose power so at highway speeds, you might even get worse mileage because these trucks push so much wind. 3.73's may make the engine work harder to maintain speed. Elevation also can come into play for power.

I don't suggest cutting/welding/piecing together any pitman arms in any way. Do it right and safe.

[Ski-me]

At 4800' in Carson City, I'd want (and have) 4.10's. I actually swapped from 3.73's to 4.10's and do much better at my elevation (6500').

Now if I were in Seattle....I'd have a rocket! Love that sea level power!

Oh, my boat also came from Carson City pawn shop. Excellent boat!

[andrewmp6]

The front springs will only work one way flipping them over will probably break them.As far as the steering box i believe they turn different ways 2wd and 4x4 and cutting and welding a pitman arm don't sound safe to me.You could use the 4 inch springs and maybe take a leaf out but it will change the spring rate so its a crap shoot on how it will ride after.

[Smogmonster]

thanks guys
so im curious im not doubting you but am i missing something? why cant i flip the springs can somebody explain?
i can see that you may need to cut the lower one and re locate it. will they NOT
fit up the other way? even if i flip the locating pin? its common to flip springs ive done it myself but never done it to one of these

ref the pitman arm im not happy about doing that either really its not ideal allthough i have done this before with no problems and so have others

so what steering boxes from what year will fit as theres no 91,s at the yard i use
please advise if i need to use a thread adaptor for the hoses or what the quick fix is to mate it all together.maybe swap the union on the pump to match the box hoses?

axles
my truck is a diesel and my old truck had a similar set up with 3.54 gears and even had taller than standard tires and was just fine on the highway and long towing trips it did have a little more power though. but 60 mph @ around 17-1800 rpm was nice and i rarely needed to rev it past 2k
but this thing is revving higher with 4.10 and shorter tires. and on long trips mpg is king.


the engine power is the same regardless of axle ratio it just moves the ,,sweet spot,, and right now 1st is almost useless
but i dont particularly want to install this heavy 14 ff axle i have when a sf will do

im not sure about the elevation and running issues regards a diesel engine up here but i guess it still prefers lower altitudes

thanks again

[Smogmonster]

so i guess thats another dead end thread then.
i looked again at the springs and the way they are made would suggest that flipping them could cause the end to pull apart as it doesnt wrap around the bush fully when upside down
( for anybody else googling and wondering)

[jetmech85]

I can't help you with springs and flipping but your steering box needs to be from a 4X4 and have O-ring connections not inverted flare fittings. I think they went from flare to O-ring in 1979. So, you should be looking for '79 to '87 and up to '91 Sub, Blazer, Crew four wheel drive steering box. There is also the option of putting new seals in your box because you not only have to find the box you also have to find one that does not leak, good luck.

[Smogmonster]

thankyou jet thats very helpfull.
i actually have a seal kit for the 91 sub but i dont want the downtime and the other box
i picked up is allready off and appears to not leak.
for others in this situation i will update this when i try the swap
thanks again

[Smogmonster]

ok so im looking underneath swapping in another steering box and i can see i have several bad bushes so its a case of the may aswell while im here scenario.

so i was at a friends yard and he has a gas burb down there 4x4 but it has regular bend smiley not frowny front diesel leafs like mine so would it be a good idea to fit those to mine? and maybe add a leaf from some old rears i have here? il have to remove them and buy them and maybe re bush them so..... first up

who has the best deals on bush kits? and would you buy these used springs or just buy new and be done with it and who would you buy from?

i only want maybe 1 -2 inch of lift over o.e simply due to the added weight up front