1970 c20 l9h 6l90e
 

Hello.

A few weeks ago I blew the motor on my 1970 Chevrolet C20 so you know what that means.

I just bought a 6.2L L9H with 6L90E complete pullout with 7,000 miles from a 2013 Chevrolet Silverado 1500 crew cab four door. VIN code 2 (L9H Flex Fuel). Head casting number is 823.

Motor should be shipping today so I am looking forward to picking it up and getting started.

This is also my first post.

Re: 1970 c20 l9h 6l90e
 

Welcome to the board. Hope your swap goes smoothly.

Post pics, and don't be afraid to ask questions.

Re: 1970 c20 l9h 6l90e
 

Here is a picture of the motor/trans pullout I purchased.

http://i1320.photobucket.com/albums/...ps7f65d1e9.jpg

Re: 1970 c20 l9h 6l90e
 

The engine has been crated and shipped

http://i1320.photobucket.com/albums/...ps825b6077.jpg

http://i1320.photobucket.com/albums/...pseac2cd76.jpg

Re: 1970 c20 l9h 6l90e
 

Here is a picture of the truck

http://i1320.photobucket.com/albums/...ps1ae8802c.jpg

Re: 1970 c20 l9h 6l90e
 

Ok, people love pictures so I will add a few more up to my current progress....

Here is the old motor that I threw a rod on.

http://i1320.photobucket.com/albums/...ps4aaa8128.jpg

Pulling old motor

http://i1320.photobucket.com/albums/...ps7a7e534c.jpg

That looks bad...

http://i1320.photobucket.com/albums/...ps3b6f789c.jpg

lets take a closer look
http://i1320.photobucket.com/albums/...psbe6c76e9.jpg

m22 4 speed.

http://i1320.photobucket.com/albums/...ps4e1a624e.jpg

Now I have to use an air chisel to remove that transmission crossmember.
http://i1320.photobucket.com/albums/...ps31a7e941.jpg

Transmission Crossmember removed, engine bay is pressure washed. Good enough for me.
http://i1320.photobucket.com/albums/...ps7a438006.jpg

Re: 1970 c20 l9h 6l90e
 

I have dropped the motor and transmission in to check for fitment and it looks real nice but the motor mounts don't quite fit.

http://i1320.photobucket.com/albums/...psc4142275.jpg

Re: 1970 c20 l9h 6l90e
 

I currently have the $30 eBay motor mount adapters using stock motor mounts and the problem is that its placing the motor mounts about 1/2" to 3/4" wider than stock so bolt holes aren't lining up

so.. I am trying to figure out a new solution for motor mounts...

I see muscle rods has a nice kit but $$$$$ .... $280 or $479.00 including transmission crossmember and mount.

Performance Online has a nice looking kit for $129.99 thats looking to be the best option right now.

anyone else have ideas?

Re: 1970 c20 l9h 6l90e
 

anyone know how I can edit my first post here in this thread so I can keep most up to date info/status in the first post of the thread?

Re: 1970 c20 l9h 6l90e
 

I used stock 73 up clamshell mounts on mine. I already had a pair of these with my truck. I'll see if I can dig up my pictures. I only spent a few bucks on the adapter plates. My engine fit great, but as you probably already know you will need a high hump tranny cover.
Edit: you can see pictures of my setup starting : HERE

You have to be a subscribing member to edit posts after a few minutes (I think).

What did you have to pay for you 6.2 6L80 combo if you don't mind saying.?

Re: 1970 c20 l9h 6l90e
 

Thanks for your reply mcbassin.

I ordered the performance online mounts already because I want to get the show on the road. After further consideration I think I would have rather ordered the ECE mounts. I saw your comments about 73+ clamshell last night but I did not want to have to deal with trying to hunt those down, If at all possible I would like to have this thing rolling by November 1 but I think that is a tall order.

For the same price I could have bought a brand new LS3 430HP from Jegs but then I would still need a transmission, torque converter, flywheel, starter, alternator, power steering pump, AC compressor, all the brackets to hang them on the motor, wire harness and ECU.

This combo has 7000 miles on it so it should be as good as new.

Sometimes I wish I had just bought the LS3 from jegs because then I could use Holly EFI. with this combo (VVT and 6L80E) I am limited to stock ECU or Mast Motorsports M90 but they don't respond to emails so I am going with stock ECU

Re: 1970 c20 l9h 6l90e
 

If you can weld, bolt plates to the crossmember and adapt to the late motor mounts. Not too hard, and you can put it wherever you want and clear everything. You can see what I mean in the Yeller thread. There is an LSX swap section on the site with tons of good info. Great build!

Re: 1970 c20 l9h 6l90e
 

I don't have a welder, when budget permits I plan to buy a millermatic 211

Re: 1970 c20 l9h 6l90e
 

Look what got delivered this evening...

Performance Online motor mounts and perch

http://i1320.photobucket.com/albums/...psd6dfa9a7.jpg

Re: 1970 c20 l9h 6l90e
 

Upon closer inspection it appears the weld on one side of each perch is getting in the way of the motor mount...

http://i1320.photobucket.com/albums/...psb5e526b4.jpg

With the motor mount as close as it gets.

http://i1320.photobucket.com/albums/...ps13f7916c.jpg

Out comes the cutting wheel...

http://i1320.photobucket.com/albums/...psf8bf0f33.jpg

And now the motor mount fits on the perch.

http://i1320.photobucket.com/albums/...psc172915a.jpg

Re: 1970 c20 l9h 6l90e
 

I got the motor mounts and transmission cross member installed today.

These performance online motor mounts were not lining up either but after a little wiggling I finally got it mounted up. Makes me wonder if I could have given a little more elbow grease and mounted it up with the stock mounts. I have no regrets.

Here are some photos.

Here is driver side mount from a couple different angles.

http://i1320.photobucket.com/albums/...ps279795c8.jpg

http://i1320.photobucket.com/albums/...ps9e2e5371.jpg

CPP Transmission Crossmember and transmission mount

http://i1320.photobucket.com/albums/...ps38281cdd.jpg

http://i1320.photobucket.com/albums/...ps01f43094.jpg

And it is all mounted up....

http://i1320.photobucket.com/albums/...ps57192096.jpg

http://i1320.photobucket.com/albums/...ps12331245.jpg

http://i1320.photobucket.com/albums/...psfc890d6e.jpg

Re: 1970 c20 l9h 6l90e
 

So, I attempted to install the stock manifolds that came with the engine (2012 Silverado). The driver side fit but is touching the frame so I would expect it to rub and the passenger side will not fit without notching the frame. I do not want to notch the frame. Doing a little research it seems the Camaro or Corvette manifolds should fit so I bought a pair on eBay. Still awaiting delivery.

I also ordered some electrical wire to finish up the wire harness with the help of documentation on lt1swap.com and their Facebook page.

Re: 1970 c20 l9h 6l90e
 

This thing is going to be a runner... Sub'd

Re: 1970 c20 l9h 6l90e
 

Very nice progress on the powerplant install.

Re: 1970 c20 l9h 6l90e
 

Thanks, progress is slow but I am making progress. Unfortunately the cheapest I could find the all of the electrical wire in one place required the minimum purchase of 250' of wire for each selection...

12 AWG RED
16 AWG GRAY
16 AWG PINK
20 AWG ORANGE
20 AWG PINK
20 AWG BLACK

So I will likely have more than 240' of each left over.

Also, I ordered Automotive Cross Link TXL Wire which is the same high quality wire that Painless uses for their harnesses. It exceeds OEM specifications for underhood heat. This is better than the "primary" wire found at most parts stores.

Cross-link wire meets SAE J1128 standards and is designed for applications where higher heat resistance is required.

Re: 1970 c20 l9h 6l90e
 

Sounds like you are going to build your own harness from scratch? That would be much cleaner than reworking the stock harness. I would imagine all the connectors and wire will be quite expensive though.

Re: 1970 c20 l9h 6l90e
 

Not going to build my own harness from scratch but I couldn't find a decent price on shorter lengths of TXL wire. If I had bought 25' lengths it would have ended up being almost the same cost.

Re: 1970 c20 l9h 6l90e
 

Feeling defeated tonight. I received the LS3 exhaust manifolds today and they do not fit either. WTF

Re: 1970 c20 l9h 6l90e
 

This is a complete rework that makes this swap much easier.

http://www.currentperformance.com/sh...-modification/

here is what I bought that helped me with my modified harness

http://www.currentperformance.com/sh...erelay-module/

hope this helps with the wiring decision.

As far as your exhaust manifolds, I used trailblazer SS manifolds and only had to trim a very minor piece from the right side of the frame. You should be able to see it on page 3/4 of my One Owner Short Step build thread.

Re: 1970 c20 l9h 6l90e
 

Do you have any pictures of the LS3 manifolds in place? I really thought these would fit too.

Re: 1970 c20 l9h 6l90e
 

+1

Re: 1970 c20 l9h 6l90e
 

I did not take any photos. I guess I can do that. I was thinking about maybe relocating the engine 2.5" to the rear by bolting the motor mount perch to what I understand to be the 6 cylinder mounting location and see if that makes any more room for the exhaust manifolds. Either that or I may try out the hooker headers cast iron manifolds. Part number 8501HKR or ceramic coated 8501-4HKR

Re: 1970 c20 l9h 6l90e
 

The Hooker swap manifolds will work and fit great

Re: 1970 c20 l9h 6l90e
 

I took a photo and then I removed the heat shield and tested fitment without it and it was closer to fitting but still no luck.

Here are the photos....

This is with the heat shield obviously. I have a loose bolt in the first flange to hold it in place, the rear of the manifold is sitting about 1.5 inches above where it needs to be...
http://i1320.photobucket.com/albums/...ps5b472cbd.jpg

Now here is a photo with no heat shield. It's close, but no cigar. All of the bolts are in, I started to tighten the bolts but the collector flange is binding on the upper frame rail from below.

http://i1320.photobucket.com/albums/...ps195be4af.jpg

Re: 1970 c20 l9h 6l90e
 

those don't look different than the Camaro headers I have (2010+), I wonder if they are Corvette ? Here's some pictures of mine.

Re: 1970 c20 l9h 6l90e
 

I assume you meant those look different than the camaro headers you have.

You are right, they are different, and from my research I think they are LS2 exhaust manifolds. Those Camaro manifolds you have look like they would work. Are you using the ECE motor mounts?

Re: 1970 c20 l9h 6l90e
 

That's correct. Those picture are of my Son's 68 with a Porterbuilt setup, so the clearance should be similar to yours. I think the 2010+ Camaro manifolds will work.

Re: 1970 c20 l9h 6l90e
 

I am still trying to decide between 2010+ camaro exhaust manifolds or just buying the hookers. People are just asking too damn much for a pair of used exhaust manifolds ($150-$200) and I figure the hookers probably flow better.

Re: 1970 c20 l9h 6l90e
 

Go with the Hookers they come in different coatings as well

Re: 1970 c20 l9h 6l90e
 

You can usually get them for about a $100 shipped on the Camaro5.com website.

Re: 1970 c20 l9h 6l90e
 

So, I spent $141.25 on eBay for the wrong exhaust manifolds (That includes shipping).

I immediately listed them myself when I realized they would not work for me and sold them for $100 + $20 shipping. Paypal took their cut of $3.78, eBay took their cut of $12 the actual ground shipping charge was $44.45 so I recouped $59.77 from my initial $141.25 investment. So I only lost $81.48 on the deal.

Re: 1970 c20 l9h 6l90e
 

I used LS1 manifolds on mine and the worked good. I thought I read trailblazer SS manifolds work good too.
I believe the height of you engine is critical for everything to fit right too. I used the clamshell mounts which raise the
engine up. It also made me have to use a high hump.
BTW, have you checked into the LS-1 site or trailblazer ss site? there are guys that will sell manifolds cheap on there
when they upgrade to headers.
Good luck

Re: 1970 c20 l9h 6l90e
 

I am using the clam mounts also, they bolt directly to the perch from performance online. I think if the engine sat a half inch lower the LS2 exhaust manifolds I bought would have fit. I did not look on any forums, only ebay and craigslist. I went ahead and ordered the hookers with ceramic coating.

Re: 1970 c20 l9h 6l90e
 

When I got home from work last night the hooker manifolds were waiting for me...

http://i1320.photobucket.com/albums/...ps6cd17577.jpg

Here are a few photos of them installed. They fit perfect with plenty of room to breath. I think they look pretty damn nice too.

http://i1320.photobucket.com/albums/...ps3ec2a5c2.jpg

http://i1320.photobucket.com/albums/...pse8ebe925.jpg

http://i1320.photobucket.com/albums/...ps04ab9a0f.jpg

http://i1320.photobucket.com/albums/...ps323563e4.jpg

Re: 1970 c20 l9h 6l90e
 

I am ready to move onto fuel now. Is anyone running the stock tank behind the seat with an inline pump?