My girlfriend and I have an '81 blazer. My first chevy, and our first toy car. It's got a 350 replacing the original 305, an automatic transmission, and 4wd. Oh, and the prerequisite rust. I have not yet dug any further. What do I have? How do I find out? What's it capable of stock? What are the weak links?

We'd like a streetable trail rig. It will be a backup car in the unlikely even one of out Cummins powered Dodges breaks down. It will also be our 4x4 excursion vehicle. Not rock crawling, but just general traveling 4x4 roads, off road, and the occasional trail. I'd like to be able to keep up with stock jeeps with ease.

w/the stock backspacing, any tire upgrades will hit the inner fender HARD in the back. So think about that... front fenders need to be trimmed but then you can fit 35's w/no lift. :D

Everything is pretty cheap for these things, and cheaper if you buy used. Doubler parts are relatively cheap to come by, or you can swap in a later NV241 with its 2.72:1 ratio and be alright. One ton axles are nearly a direct swap: you'll have to move the perches on the 14bolt.

Your mileage will always suck. :D

I'd like to be able to keep up with stock jeeps with ease.

um.. so whats the challenge?

oh... you might have to replace some body panels, as jeeps are narrow. other than that, i think you have em beat.

Make it light, beat the tar out of it, and you will find what is weak.

you have a pair of 10 bolts, with 28 spline axles, an np208 transfer case, a th350 trans if an auto, sm465 if manual trans...

youre going to break the front end one day. find a later model setup with 30 spline shafts to install, or a dana 60 front/14 bolt rear axle setup when you get beyond the 35s. the only perches you will have to move are the ONE TON axle perches, 14 bolt 3/4 ton perches match up. grind the lip off the bottom of the 14 bolt for clearance.

after 8 inches of lift, install crossover steering.

when the np208 grenades, the np241 from an 88 or later blazer will bolt up.

keeping up with stock jeeps??????:shaking:

Even modified Jeeps ain't got shit on a fullsize. Except being lighter, they sometimes make it through mud holes easier.
Here in Hawai'i, very few people run full size trucks. Mostly jeeps, toyotas, and samis.
And the trails and shit that we wheel on, while they are hanging wheels and rolling over, I'm flexin right through the nasty shit.

Some type of rear locker will markedly improve the offroadability.....although with that 10b it leads to another chapter...LOL. Seriously, if you're easy on it it may* last.

*Mileage may vary.

Not flaming here, but I think www.ck5.com is more suited to your ability and stage in 4 wheeling. This site is more suited to guys that have the basics down and more towards the hardcore stuff.
ck5 is an awesome place and has tons and tons of info on Blazers. Ohh btw: they don't flame there for noobie questions.

Not flaming here, but I think www.ck5.com is more suited to your ability and stage in 4 wheeling. This site is more suited to guys that have the basics down and more towards the hardcore stuff.
ck5 is an awesome place and has tons and tons of info on Blazers. Ohh btw: they don't flame there for noobie questions.

x2 ck5 is an awesome place with friendly people.

Great resource. You're right, I'm not into serious wheeling, but who better to ask about weak links than those who are?

If you arent into serious wheeling and we are dont you see a conflict?

A 10 bolt up front(28 splines), a 12 bolt out back(30 splines), a np208 transfer case, and a th350 auto trans.

I'm thinking 35-36" tires.

How do I tell the difference between a chevy 305 and 350? And what are the ck5, k10, etc I keep hearing?

A 10 bolt up front(28 splines), a 12 bolt out back(30 splines), a np208 transfer case, and a th350 auto trans.

I'm thinking 35-36" tires.

How do I tell the difference between a chevy 305 and 350?

take the heads off and measure the bore...



or, do some searching. Theres a way to find out. you could do some basic searching on wiggitywiggitywiggity.GOOOGLE.Commies and find out.

and if its got a 12 bolt in the rear, it didnt come with that blazer, not in 81. Not saying you dont have one, just saying it wasnt original equipment for that year.

The 350 was supposed to be after the fact also. Any visual way to check if it is limited slip or locking?

ck5 is a web site, a k5 is a blazer, a k10 is half ton truck, k20 3/4, and k30 is 1 ton.

The more I look into it, it sounds like the blazer is fine for light offroading stock. Wheel it 'til you break it is starting to make more sense.

stock jeeps :shaking:

stock jeeps :shaking:
LOL, isn't the newer... rubicon pretty well outfitted in stock form?

LOL, isn't the newer... rubicon pretty well outfitted in stock form?

Yeah, buy for the money you could build a bad a$$ buggy.:flipoff2:

its probably not locked up but you could jack up both rear tires spin one side and generally if its not locked up the opposite side will turn the opposite direction also as far as finding out if its a 350 there are some numbers some where on the block that you can cross refrence at most auto parts stores

if you know its the stock motor i think you can go on ac-delco's website and type in your vin, it should bring up everything...