70' GMC "Walter"

[skyjgmc]

Meet Walter he's a tired old gmc that I saved from the scrap heap. I picked it up not running for $500 towed it to my house and thats where this story starts.


maybe I should give a little history Ive always loved this body style of trucks I grew up driving a 70 gmc (mint green) just like this one on our dairy farm and we had a dog named Walter that always rode in the back (now you know where the name came from) anyways since I was little I have wanted another one, this one will be a father son project. My oldest is 11 and wants to restore and drive this truck to high school. we've got big plans for him but for now its just collecting parts and enjoying the **** out of it before we dismantle and rebuild. so sit back and hope its not a boring ride.

As I said earlier this truck was none running lady said its got no spark, so i ordered me up a new shiny cnc billet HEI dropped it in place and it fired right up didnt even need to adjust timing slapped a edelbrock 1406 carb on it and calleed it a day.


but then my son said "dad it looks like a grandpa truck!" so i found some flashy wheels and tires. Ah much better!!

then we procedeed to use the heck out of ol walter




then I got a crazy idea to put power disc brakes on him, and that when our problems started

I had spindles and rotors off of an old j10 truck i had everything bolted up fine

bought new gm half ton calipers and pads new hoses from 1 ton truck and new lines ran to the front wheels. new booster and master only thing I got used from a bone yard is the proportioning valve and left the rear drums alone. everything went smoothly and I gravity bled the brakes then the conventional way with one man pump/hold pedal while other loosens bleeder and it drove around great for a month but now after its sat for a day I get in and run down the road and I get a soft pedal and feels like its going to the floor never lose brakes just farther travel like air in the lines if I let off the pedal then its firm again for the remainder of the drive. backs lock up sometimes if I dynamite the brakes Im not losing fluid and I dont have any leaks. Im wondering if the proportioning valve is sticking and its not effectivly working its the only thing not brand new on the brake system. the truck stopped great before I just wanted power disc brakes. any help and insight would be appreciated.

and a little teaser of what we may do with the bed since its so trashed anyways. just an 8" bob.

[swamp rat]

First welcome to the build thread and nice score on the truck!

A quick search turned up some possible threads, have a read and see if ya can find an answer.

Personally i wouldn't cut the back of the bed off, it don't look right.

[skyjgmc]

Originally Posted by swamp rat

First welcome to the build thread and nice score on the truck!

A quick search turned up some possible threads, have a read and see if ya can find an answer.

Personally i wouldn't cut the back of the bed off, it don't look right.

Thanks for the welcome! I've done a bunch of searching and it seems the general consensus with soft pedal ( after power disc swap) is the back brakes need adjusted or the wheel cylinders are letting air past but not fluid, or that the there isn't enough travel in the pedal ie; connecting rod from pedal to booster isn't long enough, or some even drill a new hole 1" lower/closer to firewall.
*Recap I swapped new power front brakes with new hard lines new hoses new booster/master and used a proportioning valve from a 74 chevy with disc/drum out of a junk yard gravity bled system then conventional way and now get a soft/spongy pedal right after first start up and first time applying brakes, but then get normal operation rest of the drive.

[flashed]

Im in to see more of Walter .

[skyjgmc]

Originally Posted by flashed

Im in to see more of Walter .

Thanks we have big plans for Walter. He's got a tired ol 307.


I did get my hands on a 1999 chevy work van with a 5.7L vortec in it so as of now plans are to swap that in. Can't decide if we want to keep the 465 or go auto but I prefer my kids learn how to drive a manual. Just hope the 307 will hold up long enough to get this one ready to drop in.

I'm no stranger to engine swaps and fabrication over the last few years my boys and I have built a jeep. Here is a link to my build thread over on jeepforum.http://www.jeepforum.com/forum/f22/s...build-1467426/

[skyjgmc]

Not a lick of snow on the ground then bam all this fell within 12hrs. It was interesting getting to my hunting spot this morning here is where ol Walter and I parked.

[flashed]

Walter looks right at home there ,I hope we dont get that crap this year .

[skyjgmc]

Ah now that makes sense why I couldn't switch from defrost to floor. kind of hard when these buggers are jambed in there. (PO)

I also replaced my duct work made knew defroster duct and got ride of that brittle oe stuff. Made it out of 2 1/2" shop vac hose works great and looks good too. I'll snap a pic tomorrow hard to see in the dark.

[swamp rat]

Jammed in the switch or in the heater box???? 7.62/308HP?

[enigma]

my guess would be ought 6 looks to long and skinny for 7.62. but alter looks like a tough truck and I would not cut the back of the bed off either.

[skyjgmc]

Originally Posted by swamp rat

Jammed in the switch or in the heater box???? 7.62/308HP?

Jammed in between the "flap" to switch from defrost to floor hear right where the driverside defroster duct comes out. The spent casings are 30-06 and the live rounds are 270

[skyjgmc]

Have'nt done much to Walter lately just been driving it a lot. I do think I got the soft brake pedal figured out, just needed more bleeding I think the prop valve was a little sticky and now its had 5 gals of fluid through it she is fine. did replace the original blower motor in it last week, its quite now. Next project is getting the exhaust on it. I have some used flowmasters to replace the crusty glasspacks the original owner installed with baling wire and bubble gum, we"ll redo the exhaust when we do the vortec swap so this will be just down and dirty to get it quite enough to hear yourself think while driving down the road.

got a big list of preventative maintance items to get done on the ol boy here soon
1. heater control levers
2. replace all fluids
3. shocks
4. new front springs
5. shackle flip rear
6. rod ends and drag link
7. new tires
8. vortec motor swap
9. interior pieces
10. new seat cover
would really like to do a duramax swap but not sure we really need a diesel it is our main tow rig but thats only the camper in the summer and maybe towing the jeep to some trails.

Oh and since build threads are boring without pics

weaksauce flex pic

at dusk

[twistedchevy]

I like it, looks good.

[skyjgmc]

Ok so it looks as if Im going to be getting serious with the ls swap in the next few months Im not afraid of a motor swap I have swapped a 5.2 magnum into my jeep wrangler and have successfully been beaten the hell out of it for 2 years now, and have lots of buddies who have swapped ls motors into their jeeps. Now with that said I am humbly asking for any guidance through the process you guys are willing to give. I havent done much research on the process, The motor Im going with is a 5.7 out of a 1999 chevy 3/4 work van. I dont know nor have I found much info on this particular motor... Ie: oil pan clearance?, can I use van wire harness? what types of issues will I run into with mating it to my 465 transmission? what manifolds to run etc........I plan to use as much from the van as possible IE fuel tank and pump, etc.... so if any of you know a particular thread or build that answers all of my questions I dont mind doing the reading or learning I dont want to be spoon fed I like to learn so.......

[skyjgmc]

soooo Ive been reading up on every ls swap I can find on the forum and cant wait to get this project started. It may not be as soon as I hoped since we are leaving at the end of March for Moab in the jeeps. I got a few items to iron out in the jeep before we leave, but after we get back all hell will break loose on the ol boy. Im thinking for right now we will keep the patina look and get the motor in and running well then do body work as we go or try and find another cab and bed then swap everything over when its time. I know the rockers were repaired by the PO and I can see fibergalss and resin so I dont know how far the damage is in the floor nor was his quality of work that great so Im a little concerned to what lies beneath.
For now we are using everything we can out of the van even the 3 point seat belts are in good shape and look to be easy to make work with Walter so thats one of the items first on the list is fab some belt brackets for the floor mount and get rid of the lap belts. the van has hydroboost brakes also so even after the most recent disc swap Im sure the hydro will find its way under the jeep plus the 14 bolt I just need to track down a front dana 60 but with their popularity in this day and age they are even as rare as hens teeth in these parts.

[skyjgmc]

My pooch impatiently waiting for me to get done at the bank and head home.

[skyjgmc]

So I guess I need to do a little more research before I start saying that I got an LS motor the motor in this van is just a standard 5.7 liter Vortec iron block motor, what sbc family is that considered??. It runs amazing, but the 4l80e may need a rebuild. I've been doing some research on using the 2wd 4l80e and making it a 4wd and bolting up my 205 to it since the speed sensor in in the transmission and then I won't have to worry about an aftermarket one, but still debating on keeping the sm420 since I want my kids to learn to drive a manual¿¿

Any insight on making the 4l80e 4wd?? is it as simple as removing the rear case and cutting the shaft down and bolting up the 205.or do I have to get a new main shaft?

Obligatory shot of the van I'm robbing the motor from:

[swamp rat]

I would post that trans and T-case question on the 4X4 tech and offroading section

[swamp rat]

Maybe this thread will help? scroll down about 7 pictures.

http://67-72chevytrucks.com/vboard/s...d.php?t=421030

[skyjgmc]

Originally Posted by swamp rat

Maybe this thread will help? scroll down about 7 pictures.

http://67-72chevytrucks.com/vboard/s...d.php?t=421030

Wow thanks for the help. I was reading some threads on pirate4x4 on converting the 4l80e to 4wd and some say all you have to do is remove the tail housing and some not all 4l80e have a fully splined shaft so all you have to do is cut it to length and bolt up your 205.

[skyjgmc]

the only thread I could find in relation to my question is this thread.http://67-72chevytrucks.com/vboard/s...=640506&page=2 he does just as I suggested and cut the some off the rear shaft and use the stock adapter then bolt up his 205. thats if the 4l80e in fact has a full splines main shaft. I guess we will see when I remove the motor and trans from this beast

[skyjgmc]

obligatory shot of the motor in the van, removed the dog house its not my first choice for a fuel injected motor, not a fan of the "spider injection" but it shall do.

[skyjgmc]

How the hell did that happen!? It was on when I went into town just got home and it's gone.

[swamp rat]

Somehow i don't think that just happens.....

[LT7A]

Good luck with Walter. Cool truck. That 5.7 Vortech should bolt right up to the manual trans and give you good FI torque. Could always do the automatic swap later if the 4 speed starts to bug you.