Old trucks... lets see them!

[MattS]

There are different bell housings for different diameter flywheels and clutch sizes. I am no expert on it I just know if your running an 11" clutch you need the big bellhousing. If your 87 big block doner truck is manual trans then you'll have everything you need. If it's not you may have to find a 454 flywheel/bellhousing combo.

As far as the hubs/rotors go, once you find the right one's you just swap the hub and rotor. No more work than doing a brake job. You'll need a wheel bearing nut socket for the Dana 60. I don't want to sound like a downer, but I got the feeling your truck is more likely a srw truck with a swapped out rear axle than a drw truck with swapped out front hubs. You could check your rpo codes to know for sure.

[bbaker]

Ok so it looks like I just bought a complete running 87 GMC single wheel 1 ton with a 454 and 4 speed. I havent' seen pic, but he says the cab and truck is in pretty good shape. it's only 2WD, so can I take the 4x4 stuff and dually rear end out of this truck and put under than one if it's in better shape? for 300 bucks I couldn't pass it up. I think i can sell the fleet side long bed for nearly that?

[bbaker]

The paperwork in th truck lists it as a dually. The story I got fromt he guy was he sent his buddy to pick the truck up over by lexington. He came back with it with those oddball front rims on it, due to the dually tire being flat and he just swapped the rims over to make it roll. I got the dually front rims, and just assumed that was the case, but again I haven't ever messed with this vintage 4 wheel drive truck.

[MattS]

It would be way easier to swap the cabs out. The 2wd have a different frame with coil springs and control arms. The 4wd have a shackle and reinforcement that goes through the frame for the leaf spring. I think where the steering box bolts is different too. You could convert the 2wd, but you would always have a converted truck. If you swap out the cabs you would have a factory truck.

[bbaker]

I'll just have to look it over real well and see. Isn't it funny how projects get bigger? It seems to me to possibly be easier for me at least to put the 4x4 stuff on the 2Wd frame, especially if it's in better (not as rusty shape). I have been reading up on this and it seems possible.

[Racenitro]

BBC and SBC bellhousings will interchange. Many are identical. There are some differences in 2 ton trucks becasue of dual disc clutches.

BB...I bet the front hubs are not for dual wheel (budd)type rims. Bet the rear was changed to a dual wheel rearend. There are adaptors that will extend out far enough for the rims to work.

If the front hubs were for budd wheels then the rims on it would be farther out and look real funny....

I have a suspicion that this truck started life as a SRW (Single rear wheel) truck such as pick-up. The 4x4 hub part sits back inside the hub on ost budd hubs.

[BigMike]

BB,if that were my truck I would get everything functional and use the piss out of it and work at making it pretty down the line.It looks to be in pretty decent shape but then where I live most of those trucks have been gone for 20-25 yrs.
The more you tear apart the more you have to put back together....why make yourself more work?

[rweaver]

I was a chevy salvage yard for 15 years before I started doing IH the 6cyl up to the 454 will interchange as far as bolting it together since your doing 4x4 the tranny has to stay the same is the other truck 4x4 as well there is 2 styles of transfer cases the 203 which is a chain case also fulltime 4x4 the 205 which is gear and most times used in the lockout style and in my opinion the better one even is I did not want the 454 if I would still buy the truck for 300.00 those engine bring more then that

[Jeff in Pa]

Next question is a freind of mine has an 87 GMC with a 454 Big block. I don't know much else about the truck at this point other than he wants 300 bucks for it, and it's suppossed to run good. Are the small block and Big block bell housings the same? As in, can I take the 454 and simply bolt it into my truck with my transmission? I am hoping his cab is good too, as my cab is pretty rusty on the bottom.

Bryan,
It should be a direct bolt up. Make sure you get the entire truck even if you scrap it when you're done. That way you'll have ALL the BBC pieces to convert it from your small block. ( the front pulley system is different) The bell housing should bolt up. Is the '87 an automatic ? Worse case scenerio is you would have to tap the block 1/2-13 (iirc ) for the ball pivot for the Z bar to operate the clutch. ( the latest generation MK V BB, the 502, doesn't have that boss at all and a bolt on adapter is available )

Jeff

[bbaker]

The 77 started life as a dually, I do not know where or why the front hubs were changed.

The 87 I am going after tomorrow is a 4 speed manual just like the 77. I figure if the bed is in decent shape it alone would be worth nealry what I am paying for the entire truck and then I have a nearly free 454. I am really hoping the cab and fenders are in good shape, so I can just use them in this project.

BM. I hear what you are saying, and you are most likely right. But the cab on the red/orange one isn't in that great of shape. The hood is perfect but the rest isn't that great. I will know more tomorrow when I go and get the 454 truck.

[Dbaumanjr]

The '87 is most likely fuel injected, the '77 carbureted. If the '87 is a fuely, then you'd need to change the intake to a carb intake(and carb), replace the distributor to one with vacumn advance & mount the mechanical fuel pump on it. Then you've got wiring to do. Not insurmountable, just more work.
The big block is externally balanced, the small block internally. Meaning that you can't use the flywheel from one to the other.
And yes, the frame is different between 2wd & 4wd. 4wd, the steering gearbox mounts outside the frame, 2wd inside. And the list goes on......
The dually front rotors basically have a huge cast adapter that bolts to the rotors & spaces the wheel mounting surface out. Not sure how hard these are to locate....
Hope this helps,
Darryl

[bbaker]

the 87 is supposed to have a carb.

[Dbaumanjr]

Well, make sure that it has a choke butterfly. If not, then its throttle body injected. Some people get confused by this. Also look at the fuelpump mounting boss on the rt. front of the engine. If its carbed, the pump will be there. Fuely has an electric pump in the tank.
Trying to help, since I work on these for a living.
Darryl

[bbaker]

I appreciate it. I actually hope it is fuel injected and I will just use the 87 cab with the motor in some form. And I appreciate any help with this.

[mpfeiffer]

1987 was the first year fuel injection was introduced to the Chevy full size truck line. However not all of the trucks were fuel injected. All of the 1/2 tons 4.3 v-6 305 and 350 v-8's were injected. Not all the 3/4 and 1 tons were injected however, and most of the 4 wheel drives were still carbs. This carried over into 1988 as well, when the body style changed. All of the 1/2 and 3/4 tons were the "new" body style, but the 1 tons were still the old style. All of the new style CK trucks were fuel injected.

I had a 1988 2wd four speed 1 ton dump, and it was fuel injected. a friend of mine had the identical 88 truck as mine, but 4wd and his was a 4 bbl carb still.

If the big block 87 truck you are getting is injected, you would have a lot of parts to swap. The wiring harness is different, as well as the sending units in the fuel tank(s), fuel lines etc. You could however transplant the 454 into the 77 truck, and install a new intake manifold and carb on it. You should be able to find something like an Edelbock intake and carb pretty reasonable. One thing I can tell you from experience, is you cannot stop a big block, they have endless power, but mileage is terrible. That 350 with the 4pseed behind it is plenty of power unless you will be pulling big heavy trailers all the time. My 454 got no better than 10mpg empty, and 4-6 with any load.

[Farmallgray]

BB,
Another factor is whether your 77 was a cab & chassis or a pickup. The rear axles and the frames are different widths. But That won't matter if you are putting a flat bed on. But if you are wanting to put a pickup bed on it you could have some problems. On a cab & chassis the rear wheels don't stick out any wider than the cab, while a dually pickup has to have those big fenders outside the bed to cover the outer duals. From the photos it looks like it was a cab & chassis which means it would have been a dually originally.

I would prefer the fuel injection myself. If the 454 is injected I would leave it that way if possible. To change the front sheetmetal from the 73-80 over to the 81-87 will have some minor issues too. But if you use the cab and front clip from the same truck (either one) you won't have any problems.

I like the 73-80 front end better myself just because you don't see as many of them anymore. I switched mine to the one-year-only 1980 front end for that same reason.

The dually front hubs are probably easier to find than the single wheel hubs you have now. As Matt mentioned you may be able to swap them with somone building a puller or rock crawler or something.

[bbaker]

I knew you guys would know these trucks! And Todd thanks for the forum link I signed up today and have been reading.

[jchabot]

Next question is a freind of mine has an 87 GMC with a 454 Big block. I don't know much else about the truck at this point other than he wants 300 bucks for it, and it's suppossed to run good. Are the small block and Big block bell housings the same? As in, can I take the 454 and simply bolt it into my truck with my transmission? I am hoping his cab is good too, as my cab is pretty rusty on the bottom.

Should be able to swap everything over. There's a bunch of years between them, but they share the same frame/cab design. If I remember right, even the motor mounts line up. You may have to swap out the radiator support.

[pattonacres]

BB The cab on the 87 will have the hood hinges on the cowl where the 77 had them on the fender. you will need to keep the 87 style front end or do some fab work to inter change

[jdonovan]

Bought this out of Oregon, 1966 F250 Camper Special...Joe

[bbaker]

Ok so it turns out the 87 is really an 86, but it is a big block 4 speed, and structurally is in decent shape. So just looking a things, I think I want to put the dually rear axle under this truck and 4x4 front end under it as well. From what I have read I will have to cut the hump out of the floor, bolt in the higher hump, change the frame cross memeber at the transfer case, and take out off the front suspension and bolt in the 4x4 spring hangers/suspension and have to drill new holes for the rear spring perches? Sound about right?

[Jeff in Pa]

Can you put the trucks next to each other to check out the frames ( as far as bolting components up ) ? Might have been a "typing oversight" but what about transmission/transfer case? Swap entire unit/assembly or put the transfer case on the '86 trans?

Also, what are you doing for a bed? You'll either need flares/fender extensions or the flat bed you were talking about. ( if you're really lucky, the rear in the '86 will be a perfect gear ratio match to the front rear ratio. That way you could keep the bed until you find a flat bed)

Jeff

[bbaker]

Nope want a dually and I have a flat bed I bought this weekend. I am gonna keep looking for a bed though as the one I got will work, but there might be a better one out there and the one I got was cheap. Plus the rear in the 86 is an open diff the dually diff is a locker.

[Farmallgray]

Bryan,
Before you tear anything apart, measure the frame widths and spring perch widths on both trucks to make sure they are the same. If the 77 was a cab & chassis the axle may not fit the 86. You may be able to make it work but you may need to move the spring perches on the dually axle. You may also need to space the wheels out so the inner duals clear the frame.

[Racenitro]

I would use the 427 tall deck over the 454. The 454 is an external balanced engine whereas the 427 is internally balanced.
The tall deck is made specifically for trucks and has 4 bolt mains. These were our top choice when I was building nitro burning engines for my dragsters. I used big blocks exclusively.
What you really need is a 502 that is made for towing.....awesome power and torque. Used to have one in the NHRA Division truck that I drove from Missour to Wyoming and Colorado. Pulled a fully loaded 28 foot enclosed trailer all the time. No problems in the mountains of Wyoming and Colorado.

Will bet the 454 is a 2-bolt block....

You will need to use a flywheel specific for the engine you are using....396/427 specific(internally balanced) or 454 specific (externally balanced) Also, the 45 has the large balancer whereas the 427 has the smaller balancer....very critical!

BB...
I dd a 2wd to 4wd swap in a suburban back in mid 70's. Yes...you have to cut out part of the hump. The 4x4 has a bolt in floor panel whereas the 2wd has a solid mounted flor. Front spring hangers will have to be added as the 2wd is coil and the 4x4 is leaf. I gave up and found a frame so I did not have to do all that work. Also, the 1 ton frame is probably different from the P-U frame. The springs an dmounts are different for one. Locatons of axles will be slightly different...believe it or not, the suburban vs the 3/4 to pu had differen Wheel base by 3/4".
You will need the correct cross member but the side ounts should be the same. The location of the fron tof the bellhousing I beleive is in the same poston regardless of which engine....The front is what changes....wrt position... The BBC radiator is larger than the SBC or I-6.

What did you do to impose all of this punishment on yourself. Without a garage large enough to put them side by side, this is a fair weather project....LOL...
I know as I have to do some of my work ourside as the excavator and bulldozer are both too large to put in my barn. Weather right now has me at a complete standstill. Only working on the 580B backhoe. Took a break on also cutting up the 25 ton crane chassis and wainting for better weather to compete the Model R Mack Tandem Dump Truck. Replacing Radiartor and have to fabricate since it was retrofitted with a 3208 Cat...

[bbaker]

Frank, the 454 is complete and running.... and the whole truck was 300 bucks, so yeah gonna use the 454, and this is a farm truck not a dragster!

My buddy seems to think changing motors and cabs is the easier alternative to end up with a 454 powered 4x4 dually which is the end goal.

[Racenitro]

That wold work. Measure the 4 cab mounts . They should be the same. Most of the cabs for the 1/2-3/4 and 1-ton trucks were identical. Years may make a slight difference but I doubt it. 454 will slide right in...and since it is a manual, the flywheel will work...may need to change clutch disc and since it is open, I'd replace the clutch disc and pressure plate..eaier now than later.... also the throw out bearing...
I assume that is a Quad Jet Carb....Most mechanics will tell you you can't rebuild them...send it over with a with a kit and I'll make it purr....I made a ton while in college rebuilding them after people were told..you wll have to buy a new or factor rebuilt one....
I do have a holly Quad Jet direct replacement you could have cheap...needs kit.... swap me something for it.....
Sold all my BBC stuff early last year after I aborted my BBC Mini Rod Project... Still have a set of BBC Roadster headers...


BB...Hope you have titles for both...You will probably need to make a trip to the DMV as the Serial Numbers will not match up betweent he frame and cab/dash number plate.

[bbaker]

I'm sure it's a quadrajet. Good deal on the rebuild! Yeah I figure while I have it apart I'll get a new clutch and throw out bearing. This will be a spring time project I currenlty have a mustang torn to pieces in the garage!

[BigMike]

BB,have you thought of the Mike Toney effect?

Sorry Mike.....it HAD to be said

[bbaker]

BM as in? sell it tomorrow?