Need answers for a 1968 C20 LWB

[lucky13csa]

Hello. I made an introduction in the welcome area last night.
My questions cover multiple areas, so I chose to post this right in the main 67-72 area. Before I ask my questions I want to be clear about what I expect and I want you to know that I've spent 30+ hours browsing this forum with and without the search function. Heck, I think I know everything there is to know regarding working with the C10. Therein lies my problem: info regarding the C20, specifically, is either 1)not there 2)vague 3)confusing or 4) I simply can't find it. Here are my goals:
1)Front and rear disc brakes with hydraboost power assist. I want to either maintain 8 lugs or go 6 lugs.
2)Power steering.
3)Chevy BB/TH400.
4)Posi rear. I have an Eaton.
5)Relocate gas tank to rear.

Now, I imagine 3 & 4 would be similar to the C10. However, 1 is my biggest question. You guys talk about using a 3/4 ton lower A-arms and '88+ ball joints and front brake components along with tie rod ends. The thing is, my truck is alread a 3/4 ton. Will a newer model 3/4 ton front suspension unit(cross member and all) bolt right up? This would leave me with 6 lugs, right? Is my Eaton rearend worth working with or should I get another rear? I want to keep my rear coil setup. How about power steering? Can I use a hydraboost setup from a medium duty commercial truck? How about a gas tank(from a junkyard) that won't hang to low?
If I have to do some fabricating I will. But, the more bolt up solutions the happier I'll be. I just found out last night that I had an Eaton rearend(thanks to this great forum) and I have not researched that yet. Going to do that as soon as I post this. I know that these are a lot of questions, but I have faith in the members of this forum. I would greatly appreciate any answers or pointers in the right direction. I just hope that I will not be answering my own questions($$expensive$$).....LOL. I just got this truck for $300 less than a month ago and I love it more everyday. I have a vision of what I want this truck to be when I'm done. If you made it through this post, thank you for taking the time.

Sincerely, Mike

P.S.- I found out quite a bit about my Eaton rear end. My only question with that deals with putting disc brakes on it. Also, two other things that I forgot to mention: I do not want to buy kits from any companies. I want to do this with swapping parts and if necessary, minor fabrication. Is there and where can I get access to a GM parts # interchange book? Something that lists all of GM's part #. Thank you.

[poorboy]

You can bolt the front crossmember from a 71-87 3/4 ton to get disc and keep it 8 lug. The power srteering w/hydro-boost should work. You can put disc on the rear of a 73-87 14 bolt w/floating axles with a bolt on braket and factory calipers and rotors. You should be able to buy the axle perches to put the rearend on the trailing arms. You'll probably need to fab a panhard mount on the rearend. Here's a link to the rear disc bracket and one for the rear disc swap. I did the swap on my Blazer it's gravey.

1.3booklo.vingchemistrygeekmo.m13@gmail.com

http://www.fourwheeler.com/techartic...ke_conversion/

[lucky13csa]

Thanks for your speedy reply.
So the front should be a bolt on affair for the most part, right?
I have bookmarked the link that you have provided to me for future reference.
However, what are my options with my current Eaton rear regarding disc brakes? I have found a company that offers a kit for this rear. I think it's BlackBird. That company is mentioned quite a bit throughout this forum. Fabricating a backing plate would be easy with the measurements and a knowledge of what other factory parts(rotors, calipers, etc) would be required. I would rather take this route since I believe that it would be cheaper. Any ideas? Thank you.

[Fred T]

On the differential. The 10 bolt HO52 has one major disadvantage, gearing. 4.10 gears are the best you can do for not a lot of money. If you go with the newer 14 bolt full floater, 3.73's are available anywhere, there are even a few 3.42's out there. And you get discs if you find the right setup. I would check with the local yards before making a decision.

Interchange manuals are out there. They do pop up in the classifieds every once in a while. Some are on e-bay.

[Longhorn Man]

there is a cat on e-bay who sells the brackets and stuff you need to put disks on the back of an eaton. I have no clue who, nor cost... someoen should jump on here though.

[WorkinLonghorn]

This is going to go against the grain here but what do you need disc brakes for? Are you planning to tow a large trailer or haul a massive camper through the Rockies?
I know,it seems everybody is spending big bucks and loads of time and effort to convert.
I don't really understand this.My truck has drums all around and I can load it up with a couple tons and exit a down-hill freeway offramp at 60 MPH and stop the truck with a MAXIMUM of maybe 20 Lbs pressure on the brake peddle.
This is with vac-assist ("power") brakes.

[Longhorn Man]

I can see the need for disks in the front... but for normal driving, I see no reason for disks in the back. They will show no improvement unless you are in the mud, in deep water, or have 2500 pounds in the back of the truck all the time.
However, the drums for the eaton, are not made anymore, and haven't been made for a long time.
On my c/30 with single rear wheels, I played hell getting shoes. I dropped over 500 bucks on my drums, and still have 1 old brake cylinder, old shoes up front, and 4 old drums!
So I say part avalibility is a good reason to swap.

[lucky13csa]

A 4.10 is what I want anyways. My 427 is going to be a little high strung anyways and I'll need the lower gearing. Parts availability and cost is half of the reason with looks and coolness factors involved as well. To be honest with you, manual steering and manual brakes with drums around work quite well. It's nothing like power assisted devices without power....LOL. I'll look around on E-Bay for this person, but I would like to find a blueprint or figure out how to do my own for the caliper brackets. Fabricating those brackets would be a simple and free process for me.
I know that the BB will fit right in with the proper mounts, but do I need a short or long tailed TH400 tranny? Will either one or both require modifying my drive shaft? Also, will I need the high hump tranny tunnel in the cab?
Any ideas on a factory gas tank that won't hang to low?
I just took the head off of my 292 the other night. I'm thinking about re-ringing the engine and rebuilding the head. Got to have a truck to haul my parts home, huh?.....LOL. I'm debating on whether it would be more cost efficient to do this or just drop in a used 350 for the time being. It'll be awhile before I get my BB built($$$$).
Dang, there was one more thing that I wanted to ask and can't remember. Hate when that happens......LOL. Well, I'll chime back in when it comes to me.
Thanks so much for your help guys. You are what makes this an elite forum. Please keep it coming. Later.

[lucky13csa]

Ahhhh.....I remembered at last.....LOL.
I saw a rolling chassis in the paper, a '75 1/2 ton. How much trouble would it be to fit my cab and bed on a newer frame? Just an idea. The only reason that I would decide against it, provided it's possible and not to difficult, would be because I really want the rear coil suspension. Anyway, thanks again. Later.

[PanelDeland]

lucky, for an interchange manual go to www.motorbooks.com
Look for ISBN 0-7603-0680-X
Chevrolet Pickup Parts Interchange Manual 1967-1978
It covers what is listed on the cover and has most but not all 67-72 interchanges.There are some tricks and tips it does not include but it helps with a lot of the things.Also try to obtain a factory service manual and a LMC truck parts catalog.LMC will have higher pricing on most things than the vendors on the board but their catalog is an excellent pictorial for these trucks.
BTW the motorbooks site has tons of books for all automotive.

[Longhorn Man]

Originally Posted by lucky13csa

Ahhhh.....I remembered at last.....LOL.
I saw a rolling chassis in the paper, a '75 1/2 ton. How much trouble would it be to fit my cab and bed on a newer frame? Just an idea. The only reason that I would decide against it, provided it's possible and not to difficult, would be because I really want the rear coil suspension. Anyway, thanks again. Later.

The wheel base on teh 75 is longer, and the frame is not flat liek a 69 - 72, so you'd be doing some seriouse shimming... more like a custom body lift.

[lucky13csa]

Thanks for the info on the interchange manual. I've got the LMC catalog already. Also, I'll pick up a service manual.
Sounds like too much work to transfer the body. So much for that idea......LOL.
Thanks.

[lucky13csa]

Well, I just spent the time since my last reply trying to find the interchange manual at motorbooks. I cannot find it either by part #, title, nor category searches. I found ones for different years, engines, muscle cars, and corvettes. Could you possibly send me a link to the page displaying the book itself? For the time being I think I'm going to look around on E-Bay and see what I can find. Thanks.

[PanelDeland]

lucky,sorry about that.I have a copy and have used it a couple of times.I called Motorbooks and asked since I could not find it on their website either. The book is out of print and they have no copies left.However the young lady i spoke to suggested calling Voss Motors @ 1-888-380-9277.They might possibly have a copy.I gave $19.95 for mine just so you know if they are trying to rip you off.

[lucky13csa]

OK, thanks.

[lucky13csa]

Hey Longhorn Man, does a BB/TH400 require a high hump tunnel? Does it require different front springs? Thanks.
Took my 292 head completely apart and the valve seats are beat to heck, especially on the the exhaust side.
I bought my wife an '88 Suburban 3/4 ton. It needs some parts as well. Is the front suspension and x member from a '73-'87 Burb the same as the pick up series? It would be easier to convince the wife to spend some money if it will benefit the both of us.....LOL. Also, if I get one with a running 350 I can also swap that into my truck for the time being. For her truck I just need to replace the steering column, windshield, and drivers seat. Not to mention I could also get the TH400 for my truck or does that only come with the BB?
Thanks.

[Longhorn Man]

The assembly line used a high hump, but many of the members here say if your cab bushings are OK, then it can be done without the high hump.
Your front springs will handle the weight, and the engine may give it one to two inch drop.

[lucky13csa]

Any thoughts on the Suburban?
Are bags on this pickup anything like the air ride suspension on semis?
I used to drive a semi and the air suspension was the better ride.
I was entertaining that idea.
If the front drops I'm definitely going to have to drop the rear a little.
Well, thanks Longhorn Man I appreciate the info. Please keep it coming, any other ideas or tips that you can think of. Later.

[lucky13csa]

I noticed that the front springs have a different part # for a truck with a BB.
Control arms have to be changed if I'm going with a disc brake front spindle therefore, changing the whole front suspension is the best alternative. Is that correct? Thanks.