72 blazer ls swap

[black_k5]

So I'm fare lyrics new to the site and purchased my blazer about 6 months ago. I love driving it so much I did a lot of research on this site and decided I would try my first ls swap. I will start by saying thank you to everyone for all the info. I'm hoping that this build might help someone else. After gathering some parts I started my project right after Christmas.

Since I did not want to stop driving the truck and wanted a lift kit I decided to start with a second frame. After having it sand blasted we added some bracing to help stiffin the body for towing. I decided to use a 31 gallon tank from a 87 blazer to be able to have an in tank fuel pump. To mount it I took 2 pieces of 2x2 angle and welded them together. This aligned to the rear set of rivet holes for the bump stop mounts. The original gas tank brace will need to also be moved back to fit the tank. This aligned with a set of holes already in the top of the frame to give you a reference point.

[black_k5]

Here is some on the reinforcement I did to the frame. The biggest improvement came from boxing in the original crossmember. For that I used a piece of 2x3 square stock and cut it to fit.

[black_k5]

Once the gas tank was fitted it was time for paint and reassembly. I por 15 everything then top coated with Eastwood chassis black but had issues with drying, it took over a week to cure. Not sure that was a good combo to use. After that the 4" rough country lift was installed with 3/4 ton axles from a 86 suburban

[black_k5]

I landed a 2002 suburban with 140k miles. 5.3l and 4l60e. Since my blazer has a np203 I decided to go back to a np205 and bought the AA adapter kit. I was going to fabricate a new cross member but due to time I ordered a dirty dingo crossmember. Once that comes in I can start on the brake lines.

[black_k5]

As for the fuel system I decided on trying the poly fuel lines after reading hemi43's thread. I bought a factory sending unit for the 87 blazer and cut off the flare fittings. Dorman sells a repair kit that has 2 12" lines with the quick connect ends. You can cut them to length then use a flaring block and swage to expand the pipe. Then brazed them together with 45% silver braze. Then added an Acdelco ep381 fuel pump that plugs right into the sending unit. I still need to find a fuel filter that has the quick connects. I think the early 2000s mustangs will work.

[GMC-YA68]

Looking good so far! You did your homework!

[SPIFFAV8]

Subscribed.

[black_k5]

Thanks Keegan. The idea of a second frame and the tank setup came from you. I've probably read your build about 15 times now.

[A1971Blazer]

Nice build....I'm subscribed....
Spare frame for me too....
I just got it in the shop and mounted to the rotisserie yesterday

[hemi43]

Looking good!! You won't regret using the ploy lines, just keep them away from chaffing and the exhaust. I used a standard fuel filter like the one on your 02 donor, because it used the same connectors as the ones on the fuel sender and fuel rail. BTW, we like lots of pictures !

[71meangreenc10]

Good stuff,

Post good pics of the fuel system. I am doing the same.

Smitty

[GM man]

Originally Posted by GMC-YA68

Looking good so far! You did your homework!

Keegan, you didn't have to move your cross member to mount that 31 gallon tank, did you?

[1rippen6]

subscribed

[GMC-YA68]

Originally Posted by GM man

Keegan, you didn't have to move your cross member to mount that 31 gallon tank, did you?

Yes, I moved it back a few extra inches but forget why. It may have been because the filler neck would have been right in the way of the body mount.

[black_k5]

Yes the cross member needed to be moved back or the gas tank would be over the axle.

[black_k5]

Alright so I got the dirty dingo crossmember and proceeded to paint and assemble it. There are quite a few bolts. Also I'm showing the holes that had to be drilled in the frame to mount it. Notice that you use one existing hole to mount it and one of the other holes gets very close to an existing one. Theyou do provide plates that go on the outside of the frame which I haven't installed yet.

[black_k5]

Here is the motor installed. I used anchor 2292 motor mounts off rockauto for the frame. As for the motor side I ordered a set of IFS mounts to save some money from the dirty dingo mounts. I had to trim the tabs off the passenger side anchor mounts to allow for easier install. Since I'm running a truck pan it was very close to the crossmember as others have stated it would be. It the wording on the pan was grinder down it would allow for more clearance. I added 2 3/8" washers between the motor and IFS motors which comes out to around 1/8". I thought about making a steel plate for a spacer but the washer aren't loosing any surface area for mounting.

[black_k5]

More pics

[black_k5]

So the only issue I have now is the secondary transfer case mount, which I know was not standard on all blazers does not line up. The crossmember came with the frame so I know it's correct. The transfer case was a Craigslist find and came with the secondary bracket. I believe the transfer case is stamped 72 though and the rubber mounts are new. It's looks to be about an inch off. I'm not sure if I should shim up the transfer case or just not use the other mount. Any ideas?

[1rippen6]

I see the rubber mounts on the front tire take a picture installed on the inside of the frame rail maybe something there is switched around. I know someone will know how it should look if not I can find the picture in the body and chassis manual if it comes to that.

[GMC-YA68]

My bracket looks like it comes down further than that (I think). Do you have the rubber mounts in between the bottom of the t-case and crossmember installed?

[GMC-YA68]

Here is what mine looks like. Maybe suck the bracket mounts down? I don't see any vertical bolts on yours.

[black_k5]

Dwyane, I am just holding the bracket in that picture. Friday i will mount it in with the rubber. I looked at a few pictures of this site to see how it mounted

Keegan I do have new mounts between the crossmember and the AA adapter mount. I did not take a picture of that but there there.

[GMC-YA68]

Originally Posted by black_k5

Dwyane, I am just holding the bracket in that picture. Friday i will mount it in with the rubber. I looked at a few pictures of this site to see how it mounted

Keegan I do have new mounts between the crossmember and the AA adapter mount. I did not take a picture of that but there there.

Mount the bracket with the rubber and see where you compare to the pics I just posted. I have another bracket that is 72 correct if we still think that one is too shallow...

[black_k5]

Your not hijacking, as all the questions you want. I also could not find that info. I started my own mounts then gave up. So it was easier for me to reference the head. With a straight edge laying on the frame and touching the rear mounting bolt webbing on the block, the head is slightly over an inch. I'd say 1 1/8"

I also took a picture of the gas tank to axle spacing so show why the original gas tank brace gets moved back.