'72 K5 - BYT - 1 ton swap

[ashman]

Nice bracket!

Dykem and cardboard templates!

You have really stepped up your game and skills....

Wow, nice job on the fab work there, Josh.

Thanks guys. I do feel like I'm getting better at visualizing complex parts and turning them into reality. Some of the actual execution needs more practice, but I'm getting there.

Ps....where is the wheelie vid?

I'm still looking for a friend that will attempt to roll it in a field for me.

As to the progress over the last few days, I managed to finish my y-pipe.

The factory LS y-pipe after I cut it down. I cut off the extensions that went the wrong direction and flipped it over so I could use it on the drivers side.

In process shot. Thanks to mrk5 for the idea to use the rods for temporary placement. It worked fantastic!

The finished product.

Installed:

Cross pipe clearance:

The cross pipe is run right between the transmission and the bellhousing. There is a little more than 1/2" of clearance all the way around the pipe.

The passenger side down tube from the back:

I think I got the clearance about as close as I could for my first try. Hopefully it's high enough not to have issues with the front driveline.

Overall I'm pretty happy with how it turned out. There are things that I would do different next time but it's stuff that you only think about after you've done one so they'll have to wait for the next time. The cost can't be beat either. I'm into the y-pipe only about $50.

Tomorrow I'll be picking up my new 50 series flowmaster and getting the rest of the exhaust put in. One of the other benefits of using the factory y-pipe piece was getting the factory connector so that I can make the back half of the exhaust as a separate piece and just bolt it onto the y-pipe when I'm done.

 

[kgblazerfive]

looking good, turned out rather well

 

[ashman]

looking good, turned out rather well

Thanks man. Maybe I'll have to make a shakedown run up to hooper when it's all done.

 

[kgblazerfive]

Cool bring it on up

 

[Z71paramedic]

I'm still looking for a friend that will attempt to roll it in a field for me.

I got a guy for that...

Looking good man! Can't wait to see it back on the road.

 

[Teck]

Watching to see it running.

 

[mrk5]

Looks really good!

 

[ashman]

Looks really good!

Thanks man. I'm pretty happy with how it turned out.

Watching to see it running.

I'll get some finished video hopefully with some good sound soon.

Exhaust is finished!!

I got everything from the y-pipe back finished up today.

It might not look like a days worth of work but building new exhaust hangers to go with it and installing and uninstalling it 20+ times to get the fit just right takes a lot of time. I'm glad that is over!

Once I got the exhaust all hooked up I took it for a quick spin around the block. I got up to a decent speed, but certainly not highway speed so I couldn't test drone at speed but everything I did test sounded great! At idle inside the truck it's practically silent but when I got on it it really sounded great. Definitely a nice throaty rumble. So far it's looking like I made the right call.

When I started this I had planned to have the Midas down the street do the exhaust work but they quoted me $650. I also checked another shop that does a lot of custom work and they quoted me about $800.

Doing it myself saved me a TON of money.
junkyard tailpipe section: $9
mandrel bent 2-1/2" 90*: $30
junkyard y-pipe: $15
new 3" to 2-3/4" adapter: $3
new 2-1/2" pipe 18" long: $7
new 3" pipe 18" long: $7
new cat: $70
new flowmaster series 50 muffler: $125

Total: $266

I'm fairly certain that what I created probably wasn't as good as what the custom shop could have done, but I'm just as certain that it is better than what I would have gotten from midas. Time is worth considering too but a whole lot of my time was spent deciding exactly what I needed to do. I'm sure if I was to do another it would go significantly faster.

I hit another shop milestone too.

Time to refill my welding gas for the first time.

 

[76zimmer]

looks good Josh, for what a shop gets to custom make a system, you could build 3 of them! Nicely done man.

 

[ashman]

looks good Josh, for what a shop gets to custom make a system, you could build 3 of them! Nicely done man.

Thanks zim. If I didn't have a welder the cost savings for this alone would have paid for it.

Got the bumper back on.

That might not seem like much of an accomplishment but it's significant for a couple of reasons.

First, the bumper hasn't been mounted correctly since I put the body lift on more than 10 years ago. It's been crooked, missing some of the brackets and too low the whole time. I had to modify the front frame horns a bit in order to get it into the right place but it's finally done and straight!

Second, it's significant because it is the LAST piece I had to modify before putting it back on to make this whole project complete. Tomorrow I'll put the hood back on and for all intents and purposes, I'm done!

I still have to fix my gauge issues of coarse but the engine runs great, isn't throwing any fault codes and all modifications are done. No more dirty work, just a bit more time checking over wires.

One other thing.

First time I've ever had one of these things disintegrate on me. A little scary but score one for a full face shield and leather apron. I took no damage.

 

[y5mgisi]

Exhaust turned out awesome! Great work!

 

[AJs72K5]

Nice job on the exhaust!!

 

[NorCalKid]

Looking good! I am running a pretty similar setup on my '71. Using that stock flange is the way to go

 

[ashman]

Thanks everyone!

Using that stock flange is the way to go

absolutely. I'm very glad I went and picked one up. Just being able to disconnect the back half of the exhaust from the y-pipe made it possible to get everything a lot tighter imo. Not to mention a lot less of a pain in the ass!

Progress:
I got the hood back on. After all this time without it on it kinda looks funny with the hood closed.

On the wiring front, I got the tach working. I used an 800 ohm and 1k ohm resistor to create a voltage divider and step down the 12v I had available at the gauges already to 5.33v (700ohm would have been closer but meh). Then I ran the 5v through a 10k ohm resistor to the tach signal. worked like a charm!

I traced out the MIL signal and the ground is indeed coming from the PCM, but it's not throwing codes.

I haven't played with the speedometer yet. I'm going to try driving it with the torque app running to see if the PCM is receiving my VSS signal at least then go from there.

 

[K85 Octane]

One other thing.

First time I've ever had one of these things disintegrate on me. A little scary but score one for a full face shield and leather apron. I took no damage.

Yeah, I've been pretty lucky so far. My coworker, even with the face shield, ended up with about a 3" nasty scar across his collarbone/shoulder area from one. So now nobody at work uses the thin ones, they all would rather struggle with the 1/4" thick ones lol

 

[K85 Octane]

Also hope you like the 50 series. I think it sounds good but some times I'm in the minority using FM.

Do you run carpet or side panels, etc? If you don't run carpet, a rubber bed mat helps tremendously with unwanted sounds/ heat

 

[MAX89K5]

Thanks everyone!


absolutely. I'm very glad I went and picked one up. Just being able to disconnect the back half of the exhaust from the y-pipe made it possible to get everything a lot tighter imo. Not to mention a lot less of a pain in the ass!

Progress:
I got the hood back on. After all this time without it on it kinda looks funny with the hood closed.

On the wiring front, I got the tach working. I used an 800 ohm and 1k ohm resistor to create a voltage divider and step down the 12v I had available at the gauges already to 5.33v (700ohm would have been closer but meh). Then I ran the 5v through a 10k ohm resistor to the tach signal. worked like a charm!

I traced out the MIL signal and the ground is indeed coming from the PCM, but it's not throwing codes.

I haven't played with the speedometer yet. I'm going to try driving it with the torque app running to see if the PCM is receiving my VSS signal at least then go from there.

Not sure how you have your OBDll wired but the Bluetooth transmitter for the torque app will not work with my set up. I have two grounds, a hot, and a serial data wire running to my OBDll port.

 

[ashman]

Also hope you like the 50 series. I think it sounds good but some times I'm in the minority using FM.

So far so good. I won't really know until I hit a freeway though. Hopefully this weekend. I'm getting it registered today.

Do you run carpet or side panels, etc? If you don't run carpet, a rubber bed mat helps tremendously with unwanted sounds/ heat

I run carpet and side panels. It made a HUGE difference from before.

 

[ashman]

Not sure how you have your OBDll wired but the Bluetooth transmitter for the torque app will not work with my set up. I have two grounds, a hot, and a serial data wire running to my OBDll port.

I'm pretty sure that is how mine is wired and it works fine for me. Could it be a problem with the bluetooth adapter? If you want I can double check my OBDII wiring and get back to you. Maybe I did it differently?

 

[MAX89K5]

Possibly, I followed the diagram on lt1swap.com. it may be my adapter..