1987 GMC V1500 Sierra Classic LS swap/build

[NastyBuzzard]

Hello everyone! I have been around for a little while now. Here and there and I finally decided to start a build thread for my 1987 GMC V1500 Sierra Classic 4x4 single cab long bed.

I bought this truck 11 years ago and it was what I drove mostly through high school. My great grandmother helped me purchase this truck so it is very near and dear to me and I will never get rid of it!

So some history. When I first bought the truck 11 years ago for $3500, 350tbi 700r4 combo w/ 3.08 gears, it was supposed to have a crate engine in it that was real fresh and so on. Well about a month after purchasing the truck, it back fired through the exhaust b/c of a stopped up cat and burnt the rings up pretty bad. It started burning oil/smoking then. Still drove it, never getting over 10-12 mpg.

Years of putting a quart of oil in it here and there it developed a bad idle issue and would die going up hills. Still drove it then until I got something else. It was then parked for a while under a tree at my aunts house. Sap destroyed the hood and roof pretty much. Came back, put a battery in, crunk it up and drove it to my new home. Still never could fix it so I put in it in my friends uncle's shop and we started building a big HP 350 SBC for the truck.

$3000 dollars later after selling my 71 maverick to fund the engine build, I had a nice built engine that was supposed to push over 400hp at the crank. Before the install of the engine I dropped the dual saddle bag gas tanks to replace fuel pumps, I thought I was going to be able to keep the tbi and fuel injection. That is when I figured out what my problem was with the truck over all those years!!! The little hose between the pump and sending unit had deteriorated really badly. So I fixed all that, but ended up having to carb the built engine we had.

Drove it around everynow and then, it would get that truck rolling!! The motor was great!! I was getting like 6-8 mpg though with a 750 holley on it.I got about 3k miles on the engine then one day after a storm I went around a curb and a tree had fallen in the road and I wrecked the truck. So we towed it to a friends and it sat there for a few years, the ubolts broke on the front p.s. side and sent front drive shaft through the transfer case.

A couple years later I finally had enough money to fix the truck, so I fixed it, got it back together, no alignment was done, put some octane booster and fired the truck up and drove it to my house. I putted it around but was always so busy with work and school it barely got driven. I eventually put a 600 edelbrock on the 350 and it was even better!! 750 was drowning it in fuel.

Fast forward a few years and I decided to take it all back to stock. I wanted the 350 tbi back so I could have the low end torque instead of all the top end HP.

Brought my original engine to the house and disassembled and cleaned it. Went off for the weekend and came back and my dad junked my entire engine for scrap!!

So I had to find a new engine, I found a 92 350tbi complete. I rebuilt it, .030 over w/ flat tops, vortec roller cam setup, stock 193 swirl port heads, longtube headers. We installed engine, drove it 5 miles down the road and front seal on trans blew. Limped it to my buddies house for the trans to be rebuilt. 6 months later, trans was rebuilt w/ oem rebuild kit, new tcc switch and torque converter.

Tried to drive the truck, had lower power issues. Didn't feel strong or have the low end grunt it used to have.

Installed a shift kit in trans, didn't really help, added corvette servos, didn't fix the issue. I even swapped in 3.42 front and rear gears. Helped some but not enough.

In the last couple months I put in a heated o2 sensor, electric fans, tbi injector pod spacer, ultimate tbi mod and pretty much anything else I could think of. Still doesn't have the low end torque she used to have. I tried datalogging to hopefully get a tune to fix the issue.

Over the last few years I have been researching and reading everyones threads on the LS swap. Well after talking with a friend, he just told me to do it. So I found me a 2001 silverado 4x4 Z71, 4.8 w/4l60e, 3.73 posi, extended cab short bed truck. It was missing font fenders, hood, doors, and bed but I put a seat in it, some gas and a battery and crunk it up and drove it around! I ended up buying it for $900.

So my plan is to take as much from the 2001 I can. I plan to swap over the entire wiring harness, using the wiring harness and fuse panel to run my headlights, door locks, power windows, brake lights, the works. I even plan to swap in the 2001 cluster into the 1987 as well. I am also planning on swapping the rearend, and swapping my d.s. gas tank w/ the 26 gal from the 2001 and getting rid of my p.s. tank and the selector valve. Also I am hoping to be able to integrate the steering column/wheel from the 2001 as well.

Any advice or insight? Has anyone seen some of this done?

Which motor mounts should I buy? Anyone have drawings so I can make my own?

I plan to get the auxiliary battery mount from somewhere to move battery to d.s.

Anyways, here is my truck!















Here is the donor: 2001 4.8 4l60e 4x4 ext cab short bed

Best BDAY present ever!!

[NastyBuzzard]

Here are some pics of what I would like to do:



This is a must for me to do. Figure out how to ge the 2001 gas tank (26 gal) into my 87 truck. I found some people who did this to a C30 w/ a diesel... Must be a way to do it on my truck.





This is what I would really like to do. Except keep stock A/C controls and keep the floor mount 4wd shifter instead of electronic. Any ideas on how to?

[NastyBuzzard]

Today is my birthday, so I took it off to tinker with the 2001. My plan is to completely modify and have the drivetrain running perfect on the 01 before I start pulling stuff to make the swap. The 87 is my only truck and I do use it on the weekends, so it cant have that much down time.

I rigged the 01 up to be able to drive around my house and even down the road by my house. Hardly any traffic on the back road near me as I live deep in the sticks!!

Ended up thinking that trans was having problems shifting, then I was getting rear end noise, so I was already worried for the worse. So I did some investigating and found this.





Rear back p.s. brake pad was completely gone. Rotor is trash. I still need to pop diff cover and check rear end, though to be sure before I order another caliper, rotor, and brakes.

Like I said, I want to make sure everything is running great before i make the swap. Trans fluid looks a little dirty so I plan to change it and the filter as well. Then clean up engine and label all of the wiring harness that I can.

[Flatpat]

Having the important parts of the '01 should help out a lot. Good luck and I think you'll find once you start digging in to it, it isn't near as hard as it seems to do.

[NastyBuzzard]

Originally Posted by Flatpat

Having the important parts of the '01 should help out a lot. Good luck and I think you'll find once you start digging in to it, it isn't near as hard as it seems to do.

I am hoping you are right!! So far I am just taking a crap ton of pictures and measurements.

I am also hoping on swapping the radiator from the 2001 to the 1987 as well. Anyone done this?

One of my friends who is a great fabricator, I am so-so but since shop burned down and I lost all my tools I am very limited, he suggests we just modify the 2001 frame to accept the 1987 body. Anyone ever seen that done?

Today, I plan to take the diff cover off the 01 rear to check everything out. I want to make sure the gears and locker are in good shape b/c I plan on swapping it into my 87 as well. Plus I want to make sure it's in good shape before I replace caliper, rotor and brakes.

[NastyBuzzard]

Took diff cover off and drained fluid. It probably has never been changed. No metal chunks or anything and teeth looked good.

[y5mgisi]

So my plan is to take as much from the 2001 I can. I plan to swap over the entire wiring harness, using the wiring harness and fuse panel to run my headlights, door locks, power windows, brake lights, the works. I even plan to swap in the 2001 cluster into the 1987 as well. I am also planning on swapping the rearend, and swapping my d.s. gas tank w/ the 26 gal from the 2001 and getting rid of my p.s. tank and the selector valve. Also I am hoping to be able to integrate the steering column/wheel from the 2001 as well.

Any advice or insight? Has anyone seen some of this done?

That sounds to me, like the entierly way wrong and complicated route to take in comparison to how simple it can be. It can be done for no more work than a simple engine swap. I couldnt imagine doing all the work your talking about... As far as the fuel tanks, if you are dead set on getting rid of the duals, just mount a 87-91 blazer/suburban tank in the back. Super simple and allows you to use a drop in fuel pump that will work perfect for your swap. I have also seen the pics of the guy who swapped in all the late model stuff that you posted and read his write up. Sounds like, again, way too overly complicated. Unless you just have to have it, are very patient, and quite smart, i would bag that idea.

Which motor mounts should I buy? Anyone have drawings so I can make my own?

Just get the CarShopInc 1" set back mounts. They put the motor in the original location in relation to the trans bellhousing and allows you to use your original motor mounts/shells. They are only i think $60. They were $50 when i bought them a couple years ago.

I plan to get the auxiliary battery mount from somewhere to move battery to d.s.

You can get those on LMCtruck and i think Rockauto sells them too.

Anyways, here is my truck!

My advice is just to keep it as simple as possible. Projects that end up overly complicated often die unhappy deaths. Ones that are completed shortly, are almost always happy.

[NastyBuzzard]

I am definitely wanting to swap over almost the entire wiring harness and fuse panel to replace the one currently in my 87. I am doing this so I can use cluster and steering column from the 01. Plus I want the relays to run my headlights and power windows and all. (All that's on relays for a reason now a days) I plan to tie in all wiring including the key fob wiring, I plan to dosregard airbags and abs though. I want to do it because I think it would be cool to be done that way and this swap is not a rush job. Also by doing this I eliminate need for sending ECM off before initial startup to remove vats.

I have been able to find ample amounts of wiring diagrams and have already started labeling and making a list of what I won't need.

I specifically want to use the fuel tank from the 01, in doing so I can keep almost all stock fuel lines or have a mix of the 2 and won't be any need for spending a ton of $ on AN fittings, new pumps, new selector valve and so on. Plus I really only want one tank that will fit in stock location to keep the fuel door. (I will eliminate the p.s. Fuel door eventually) I have seen many people go the blazer tank route and I don't want the aggravation of mounting a fill up location in the bed.

Thanks abou the motor mounts. I knew lmc sold the auxiliary batt mount but I know they usually kill you with shipping, same as rock auto. I'll double check and see the damage though.

I'm currently in the phase of getting everything to run correctly on the 01 chassis. Then I'll start gathering what little parts I need (if I can stick to my plan) then the real swap begins!! This isn't a frame off resto though! Well atleast not yet.

Also what stock truck manifolds work without cutting frame back? I have seen that the 03+ with no egr provisions look nice and smooth. Would they be better for what I am doing? Will those motor mounts you listed early work with the manifolds? Why not dirty dingo mounts for their adjustability?

[y5mgisi]

I would just use the F body manifolds.

[NastyBuzzard]

Originally Posted by y5mgisi

I would just use the F body manifolds.

I'll try and track some down. I assume I could still use the flanges from the 01 with the fbody manifolds? Are they shorter than stock truck manifolds?

[y5mgisi]

No, and they just tuck in tighter.

[NastyBuzzard]

Sounds good, I will try and track down a set. The 2001 truck I have, the original owner did have "true duals" put on. I cant find the brand name of the mufflers but I am going to try and re-use most of the exhaust pipe he had ran. It is only 2 1/4" pipe I think though. I have never ran anything that small so I am kind of worried but I feel like it will flow enough for what I am doing. He also didn't have any x-pipe or h-pipe either so I will add one of those.

I plan to swap everything over and after it is running I can drive it to a guy I know that has a mustang dyno and other software so I can delete egr, cats, and rear o2s as well as hopefully get it dyno tuned.

This truck will more or less be my truck I casually drive around town, tow some small stuff every once and a while, will rarely see the interstate but if I need to travel a long distance I want it to be dependable and get good mileage.

I am on the fence about swapping the rearend from the 2001, GMT800 body style over to my old 87. The 2001 has 3.73 gears w/ g80 locker but my 87 has 3.42 gears with an actual EATON posi unit. I just want to get the best MPG possible but still be able to tow if needed.

I haven't found any threads where someone has done the rearend swap from GMT800 to the 73-87 body style. I am sure it is just moving perches in about 2" on each side. I am also thinking about carrying over the leaf springs from the 2001 as well, I know I'd have to drill out a bunch of the rivets for my current spring mounts and move them out b/c of spring length difference, but I have heard that the longer springs provide a much better ride.

[NastyBuzzard]

GM service information website:

http://144.162.92.233:9001/si/home.do

This site gave me detailed views on everything ls, wiring diagrams, torque values, the works... For free! Check it out.

[y5mgisi]

That site, while clunky and hard to maneuver, is quite excellent.

[NastyBuzzard]

Originally Posted by y5mgisi

That site, while clunky and hard to maneuver, is quite excellent.

I agree, very hard to maneuver but if you have patience you can find some great stuff!!!

I started tacking dash out of the 2001 today. I plugged rear brake lines temporarily while one caliper is trashed. Tomorrow I will finish putting rearend back together and take it for a spin to make sure it is going through all the gears.

[NastyBuzzard]

So I got the rearend back together in the 01, I tried taking it down the road and it is not wanting to shift out of 1st gear. Time for rebuild or is it possible that something may preventing it? Also checked fluid, little off color but probably has never been changed. Didn't smell burnt but trans fluid was kinda high too. I think I may drop pan and research on how to rebuild...

[y5mgisi]

All the plug ins plugged in?

[NastyBuzzard]

Originally Posted by y5mgisi

All the plug ins plugged in?

I checked connectors and all seem to be plugged in. Maybe a wire not grounded? I need to double check. Tried to drain fluid but of course the bolt for the drain was trashed and can't even get vice grips to turn it.

[NastyBuzzard]

Put truck on jack stands and at first when cold it didn't want to shift right but once it warmed up and PCM started taking over it began shifting correctly. Still need to change fluid and filter but can get drain plug out.

[NastyBuzzard]

I have also been uplugging battery everytime after I shut the truck off due to no doors and lights staying on. So everytime I start it, it has to relearn. Got it warm and shifting when up on jack stands and took it down the road.

It would just at about 25mph into 2nd... seems a little late but I don't know if its been tuned to do so. I am going to drop pan and change fluid and see how it is then.

[NastyBuzzard]

Couldn't get drain plug out.



Had to just drop the whole trans pan. This is what I found... Not sure if I should bother flushing, new filter and fluids. Doesn't smell burnt though, looks like original delco filter as well. What y'all think..?



That "big chunk" is plastic?





Thoughts? Wasn't really budgeting for a rebuild. If I still had the shop that burned down I would just rebuild it myself.

[Jonboy]

What did the electric fans come out of that you had in the truck before the teardown?

[NastyBuzzard]

Originally Posted by Jonboy

What did the electric fans come out of that you had in the truck before the teardown?

They came out of the newer body style impala like 07+, I think. I was at the junkyard searching for fans to swap on and they looked like my best bet. I got the fans and the wiring from the car. I used my metal shears to trim plastic a tiny bit and they fit right on my stock 87 radiator. They work great!! Just one of the fans is enough to keep my truck cool, i bought a wiring kit from advanced and wired it and attached it to radiator. It was very simple. I have the second fan currently wired to a switch, b/c I don't have a/c wired up b/c of bad compressor, just in case but havn't had to use it yet.

Also, I haven't torn down my 87 yet. I want to have everything running like it should on the 01 chassis before I tear down the 87. I still need my truck so I can't afford too much down time. Once everything is running great and I have all the parts then I will start pulling stuff apart!

[Jonboy]

Cool. Thanks for the heads up.

[NastyBuzzard]

Originally Posted by Jonboy

Cool. Thanks for the heads up.

No problem. Also I could definitely feel the gains from removing the oem metal fan and clutch assy. It also doesn't put as much of a draw on my electrical system as I though. Well worth the couple hours it took me to do.