70 CST semi-project

[cst14]

Hello to all of you. Just want to say a little before I get started. I have a fan of the website for some time now and finally have something I can use here, so needless to say i am new here, and kinda new to the project world. I sould say I am average with my knowledge of this kind of thing and after reading many of the threads and bouncing them off of one of my racing buddies you people know your stuff!

I have a 1970 Chevy Blazer CST 4x4 that has been "resored" I bought the truck to turn into my daily driver. I will post pictures soon.

I would like to put in 3/4 ton axles with disc brakes so I can run 38's safely. Ive done 38's before on a 73 chevy with stock brakes. (If anyone is reading this and has never lifted anything before I ask that you definetly look into your stopping power because I had a really close call...) I found a 79 longbed I would like to use a donor truck. Its a K20 and I am curious if I can use the driveshaft out of that when I lift mine so I wont have to have custom drive shaft made.

My blazer also oversteers really bad (worse than the 73 I mentioned earlier). It is still managable, but I would like to get it fixed because pulling stuff with it is kinda difficult and you really have to drive it. The 79 donor doesnt drift as bad, so I can change that, but does anyone know of a good way to make it drive better?

Thanks for your time and reading my mini-novel. Im sure I will have more questions later. So please hang in there. haha.

[Torrey72]

Hi. I'm a new guy here too. My expertise is centered around building Chevy engines and transmissions for quarter mile drag strip racing as a hobby. I own a 59' Belair, 63' Impala, 69' Camaro, 69' Blazer with 3" body lift and 4" suspension lift (No drive train) and a 72' 4wd Blazer No lift, 33's with a 454, TH400 soon to get crossover high steering kit and a FF 14 bolt rear end up grade from a 73' camper special I also have. There are folks here on the board that are truck gods and I am more versed with the car side of Chevy. But I will help if I can. If I'm misguided, I'll get owned soon enough

As far as the drive lines go, you might get away with the stock blazer ones if the yoke mates up with the 14 bolt it looks like your putting in.( I'm guessing the front axle will just be a 8 lug disc Dana 44) But if the lengths are not long enough the 79 long bed rear drive line will be too long. But if you need the yoke off it to mate up to the axle or the tube shortened. You could have a place like "Collin County Truck Parts & Driveshaft Services" make a hybrid of the two or change the length of them for you. I looked up drive line services in Google near grapevine tx. 40 miles or so from you I bet.

Collin County Truck Parts & Driveshaft Services
2735 East University Drive, McKinney, TX 75069-0906 (972) 562-4352 ‎

To modify them you are going to need to put all your axles and suspension in the rig and get a measurement of the distance from the transfer case to the axles. The driveshaft guys can help with where to measure if you call them. Modifying the shafts isn't really a big deal.

On the steering side of things. First Gen Blazers are the victim of probably the stupidest steering geometry known to Trucks. Do a Google search for say "Dana 44 crossover steering" Look at pictures, check out what off road manufacturers have to offer. Cross over is the BEST way to go. All the coolest kids have it. Save the steering box out of the 79 C20. Cross over will not work with your Blazer box. It turns the wrong direction. If You can't swing cross over at this time. You might need to go over your front end and replace ball joints and tie rod ends anyway, or Die.

Have fun, good luck.

[cst14]

First i would like to say thank you for the advice. I am looking at a 8" lift right now and with that I know I will need to extend the drive line and i would like to beef up the yolks as well. I have talked to a guy before that built the drive shaft for my 73 and he told me that i should beef them up with as much rubber that I would like to have. The driveshaft from the longbed would still be too long? Thanks especially for the info about the steering box!