91 4l80e np 205 (I'm new)

[77nomad]

Hey guys,

I have been a member for a while but haven't been here in a looong while. I have a 86 SWb 2x that I was working a few years ago and used this place for help.

So I stop in today because I also have a 86 SWB 4x4 and it needs spring bushings. I was on Summits site and didn't know the dia. so I came back to find out. 1.5 OD? Correct?

Any how to the point. I stumble on to the 91 4l80e conversations on here. I see they are rare. Well I have a 91 2500 w/ a camper package outside that I was literally going to scrap next week. Its basically a 1ton in sheeps clothing. I have the window sticker and everything. I just wanted the drivetrain out of it at first. But now the gears are turning in my head.

Its been in my family since new, my step dad sold it to me 5 yrs ago. it runs like a top even with 250,xxx miles. The body is shot and it needs brakes. The 14 bolt drums are rusted on and I have more than enough vehicles so it has sat for over a year now. I know for a fact it has a 4l80, does that always mean it has a NP205?

My question's are what is this tranny transfer case set up worth? The adapter mainly? Should I just pull everything and do a TBI swap on the 86 4X4? I have everything except time.

The truck in question is a 53,000 mile 305 bone stock beast. The motor has "509" Vortec heads and a 700R4. Fun but still not a real small block. The 14 bolt from the 91 has 3.73's and a posi, will that bolt in? what would I do for the front axle? Leave the one in there and match the gears?

Any help will be appreciated.

[mcmlxix]

The adapter is a needle in a haystack if it is in fact mated to the NP205... its worth $300 cleaned and painted to the right person. The NP205 is worth about $150-$250 to the right person, but I only paid $75 for mine....

The 14bolt is BIG and heavy. If there's nothing wrong with what you have for axles, just leave them. Upgrade to aftermarket axle shafts and call it good. Unless you're running 37" or taller tires and heavy offroading, you dont need it.

[77nomad]

False alarm. Its a NP241. Thanks for the help.

[obijuan]

its still valuable, because its a 91 4x4 4l80. you can use a spacer onthe 241 adapter to put a round pattern 205 there.

and a 241 is valuable also because its a 32 spline VSS case. great for the 88-98 nv4500 or 4l80 guys who want to solid axle swap with a passenger drop front axle.

id just scrap the iron.


also just take the springs to a spring shop. theyll have em done in 15 minutes. its WELL worth it.

[77nomad]

I work in a full service tool and die shop. Pressing out the old ones shouldn't be an issue. Plus I don't think there is a spring shop in this town. Thanks though.

[Mr. 250r]

That 241 adapter is actually a still worth money the 88 and up round pattern 205s can be converted to use that adapter behind the 91 4l80e and vss, for any questions ask off road design they're the ones who told me about it and someone else stated, i was gonna do it but i have no need for a 205
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[77nomad]

Well funny thin happened this week. I know I said it has "509" 305 Vortec heads but in reality I was going to install them within a day of the post.

Then after clearing out an old mouse nest I got the casting numbers off the block. 14010207 This came back as a 80-85 350 block. Can anyone second that? Or dismiss it even. I know "010" blocks thats about it. Now the 305 Vortec heads are a bad idea.

I pulled an audible and tossed on a Performer RPM I had and a 600 Eddy carb. Not a screamer but it does burn the tires off. I ditched all the smog crap that has been cluttering up the engine compartment. The whole reason I thought it was a 305 was because EVERY bit of the smog equipment in tact. In this part of the country we don't have emissions testing and to find any truck from the 80's that still has it a working was a weird find. The tag says its a 305. So with the amount of rust and the vacuum lines all there I had no reason to think anything different.

I still need to recurve the dizzy because in order to get the total timing up to 34-36* the initial is just too much. It doesn't roll over the best. So I had to settle for 8* initial and 32ish total.

I was going to pull the whole drive train from the 91 but now I'm on the fence because of how well it runs. I put the tab on the carb to fix the TV cable geometry and now all is well with the truck. Any suggestions? Can anyone tel me if the tranny/t-case set up will fit with some help from my welder?

Sorry for the long post.
Damon