5.3 LS ENGINE SWAP INTO OL’ BLUE 1971 CHEVY TRUCK PART 9


Part 9 We make LED dome light from scratch, add a 3rd brake light, and reconfigure the exhaust…again.

First up, a home made DIY LED Domelight. The old one had multiple issues. 1. it didn’t work and 2. it was SILICONED into the truck…really?

Ol' Blue '71 Chevy 5.3 LS Swap

Old light (literally) peeled off the ceiling. Making a mark so I can start making a new one out of aluminum.

Ol' Blue '71 Chevy 5.3 LS Swap

Wanted two lights so I found the center vertically then the size of the hole (the bracket looking marks). After sizing the hole I found the center horizontally then divided it equally for each side. Clear as mud?

Ol' Blue '71 Chevy 5.3 LS Swap

Drill four holes, two for the lights, and two for the mounting bolts. Take my 4.5″ grinder with a sanding disc to make a cool pattern on the raw aluminum then pop in the grommets and LED Bullet Lights.

Ol' Blue '71 Chevy 5.3 LS Swap

Installed, and wired into the factory switch.

Ol' Blue '71 Chevy 5.3 LS Swap

Viola!! A VERY cheap and VERY bright dome light.

I bought a 10 pack of these bad boys in the picture below and keep them around the shop. They are super cheap ~$3/each and are bright. I plan to also install 3-4 of them under the hood for side-of-the-road emergency diagnosis.
10 NEW 3/4″ CLEAR WHITE LED CLEARANCE MARKER BULLET LIGHTS

I also used some red LED bullet lights for the third brake light that I also installed while putting the dome light in. It was quite ghetto-ly held in by those little square plastic license plate screw things… so I decided to fix it right.

Ol' Blue '71 Chevy 5.3 LS Swap

Got out my super cool thread setter tool. Think of a rivet gun that installs hollow rivets that have threads in them.

Ol' Blue '71 Chevy 5.3 LS Swap

Close up of the “nutsert” (which I believe stands for nut insert?)

Ol' Blue '71 Chevy 5.3 LS Swap

Had to make the hole in the housing a little bigger because I used a 1/4″ 20 nutsert (I like to use a common bolt size throughout the truck for easy replacement)

Ol' Blue '71 Chevy 5.3 LS Swap

Installed. You can see I added two red bullet LED’s. These trucks didn’t originally come with 3rd brake lights, but the Painless wiring harness has a wire for it so I figured I might as well use it.

Ol' Blue '71 Chevy 5.3 LS Swap

Finished assembly and tested it out. Those little lights light up really good for the price!

5 NEW 3/4″ CLEAR/RED LED CLEARANCE MARKER BULLET MARKER LIGHTS

If you are wondering why I am going on about the above LED Bullet lights being so cheap, check out the screenshot below of the LED section in the LMC truck catalog. Their turn signals and marker lights are $40+ EACH!! Mine came out to ~$3 EACH (goes to show you, a little ingenuity can save a lot of money).

71 Chevy LED Lights

Next up, some quieter exhaust. I initially used the same exhaust that I had on the big block. Though with the smaller engine it was much quieter, there was still enough noise for it to be obnoxious inside the cab. Annoying enough, that I decided to go down to the basement and drag the 70 series that I had originally bought for this project out to have another look.

Ol' Blue '71 Chevy 5.3 LS Swap

The two original flowmasters with no Y pipe, no Cats, and dumped before the rear axle = very loud in the cab.

Ol' Blue '71 Chevy 5.3 LS Swap

New (to me) craigslist Flowmaster 70 series.

I decided that doing a Y pipe under the transmission bellhousing like normal would not work due to the extreme travel of the front driveshaft. So I decided I was going to make a Y pipe after the transfer case where there was more room. Then I came up with the idea of just having a muffler with two inputs, but as you can see in the picture above mine only has one. This is the part where we get out the grinder and welder to make our own!!

Ol' Blue '71 Chevy 5.3 LS Swap

And all this time I thought there were magic leprechauns inside these things? Hope I didn’t hurt any of them.

Ol' Blue '71 Chevy 5.3 LS Swap

Traced the shape out on a piece of plate steel with soapstone

What is soapstone? Click for an article I wrote on what it is and why we DIY home fabricators use it.

Ol' Blue '71 Chevy 5.3 LS Swap

I then cut the shape out with my plasma cutter. You could do it with a grinder, it will just take longer.

Ol' Blue '71 Chevy 5.3 LS Swap

Cut two holes out for the two inputs, then welded on the female end of my 2.5″ Vband clamps.

Ol' Blue '71 Chevy 5.3 LS Swap

Then welded the whole thing onto the end of the muffler.

Ol' Blue '71 Chevy 5.3 LS Swap

Close up of the vband clamped around the two halves.

Ol' Blue '71 Chevy 5.3 LS Swap

I then threw the muffler up on some jack stands and started roughing in the tubing.

Ol' Blue '71 Chevy 5.3 LS Swap

Through some trial and error, I got the angles worked out and tacked it all together.

Ol' Blue '71 Chevy 5.3 LS Swap

Close up of the front of the muffler with the two inputs attached.

Ol' Blue '71 Chevy 5.3 LS Swap

Pulled it all apart, finish welded all of the joints, and painted.

After letting the paint dry for a day or two, I bolted the new exhaust system back up. It still doesn’t have a full tailpipe to the rear bumper yet, but that will have to come another day when I have more motivation.

And finally, click play on the video below to hear this beast in action!

Much quieter, but still throaty. I like it.

Stay tuned for Part 10… the FINAL part. I will get some outside pictures and maybe some videos.

 

Ol’ Blue LS Swap LINK INDEX:

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