Winging a 1971 K5 Blazer L96 6L90 Swap
 

Hi, everyone. Been watching this site for a long time putting my build together in my head. Picked up a tired Hugger Orange 1971 Blazer and a parts truck over the summer.

So here were go- I love the old patina paint on the truck so I think I'm going to leave the body and paint alone for now. The drive train is a different story. I plan on doing a 2" spring lift, new stock 33" tires and a L96 motor with a 6L90 transmission behind it.[ATTACH]Attachment 2162428[/ATTACH]

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Sounds cool. I will be watching!

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Looking good

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

This is going to go pretty fast for a while. I've been working on it for a little while and now just starting to post the progress to document the adventure and possible help others doing something similar along the way.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Tear down started

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Motors out

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Anyone looking for a motor

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Parts Truck

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Body is off the frame

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

This was a little nerving to have the body suspended in the air like this, but everything worked out in the end.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Cranking right along. I'd take that motor if you were closer. Keep up the good work!!!

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Built an adjustable cart, so I could move the body around the garage if needed. Space is pretty tight!!

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Ready to start striping the frame for sand blasting and paint.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Picked this 6.0L L96/6L90 motor out of a 2019 Silverado 2500hd with 4 miles on it this fall.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Frame is painted and ready for assemble.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Tearing down and inspecting the NP205 Transfer case. Found some pretty good instructional videos on youtube for rebuilding this piece.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Added a Rough Country 2" suspension lift. Rebuild both axles and swapped out the open read end with the one from my parts truck into my build, since it had a stock posi rear end. Installed all new spicer u-joints to handle the additional power I'll be putting to the ground with the L96. New drums in the rear and drilled and slotted discs up front to stop this beast when it gets moving.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Looks great, nice work

Don't forget the poly mounts on.the motor, I've read where they don't play well, if you mix poly and rubber

Now would be a good time to add hydra boost, it will stop the big tires w/o.a problem, also, consider a 3 pice cross brace motor mount, if you ever have to drop your oil pan, you will be glad you did.
Now I want drill and and cross vent my front hubs, these forums are a slippery slope
Thanks for posting up, gives me hope and incentive thar someday I'll finish mine

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Looks Good, will look in to see how your doing, My 72 K5 I purchased a year ago already had the LS1 and 6L90 but alot of things I still wanted to do such as Electric windows, door locks, 1 piece window etc. has a 6 inch lift that I would like to lower to 2-3 inch.....

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Thanks for checking out my build guys. I already purchased a Dirty Dingo motor mount for that exact reason and the rubber motor mounts. Now I'm second guessing those and considering the polyurethane ones. I'm at a good point to swap them out now, so thank you again for the tip. That is exactly why I love these forums and other builders input.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Picture of the new drums and gas tank.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Transfer case rebuilt, Advanced engineering adapter installed for the 6L90 and ready to go. Now I just need to figure out a shift linkage adapter.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

In tank fuel pump from Tanks Inc installed with Corvette pressure regulator and new shoes on stock rims. Love the look of these tires!!

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

I've got a coupe of questions about in tank pump
What part number is the one you used?
Did you have to modify depth? Tanks Inc quote max 12", where as I believe Blazer tank is around 13"
How is clearance of unit to floor, as there is not a lot of room there?

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

I used the Tanks Inc PA-4 unit. The pump will flow 255 liters per hour and handle up to 630 HP with 60 psi of fuel pressure. I'm running a stock L96 motor that produces roughly 360 HP, but eliminated the mechanical fan, added a cold air intake and plan to run stainless headers with 3" exhaust. I'm guessing the little performance upgrades will add maybe 40 additional hp. The reason I went with the larger fuel pump is that I wanted to keep the option of running e85 if I wanted and e85 requires 25-35% more fuel.

Yes, I did end up extending the reach of the fuel pump arm roughly 3/4" and extended the pick/return lines, so the unit sat flat on the bottom of the tank. I also wanted to change the line to make sure I didn't have issues if I ran e85.

I'm not sure on the clearance at this point, but figured I could drop the tank down slightly if there are any issues.

Thanks for checking out my build and I'll keep you posted when I start to fit the body.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Had to cut the output shaft on the 6L90 to fit into the Advanced Engineering adapter.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Jim- You talked me into the polyurethane motor mounts. Hoping to get them mounted permanently in the frame with the motor, trans and transfer case this weekend.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Made some good progress over the weekend. Got the motor, transfer case and transmission and LS radiator installed.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Had to make a bracket for the transfer case. installed a 3/4" adapter plate and moved the transfer case back a total of 1-1/4", which moved the motor back a 1/2". I took a number of measurement and hoping nothing will interfere with the firewall. It will be close, but I think it will be ok. Anyone out there do a similar swap and can verify the clearance?

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Eliminating the long emergency cable guide, since the cable would rub on the driveshaft after moving the transfer case back.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Dirty Dingo LS motor mount and Energy Suspension polyurethane clamshell motor mounts.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Pulled wiring harness off and sent out to Easy EFI Solutions. Using the stock e78 ecm with my converted wiring harness.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

:chevy:With the additional Horsepower from the L96 motor, I decided to build a driveshaft loop for the Blazer tonight.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

How did you modify your tank for the fuel system? Thanks

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Thanks for checking out my build 1rippen6. The tank modification is explained further in the last post on the first page of this build thread. I used the stock tank and cut the hole for the sending unit with a large hole saw. After the hole was cut I welded in the retaining ring to make sure it was a solid mount. Please let me know if you have any further questions or need any measurements.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

I'm good, I don't know how I missed it the first time, lol.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Made a little more headway tonight. Got the front sway bar figured out and mounted. Since I did a 2" suspension lift, I had to reconfigure the way the sway bar mounted. I extended the bolt and used an 1-1/4" spacer. To mount it to the frame I ended up using a couple old transmission mount brackets I had laying around. The brackets gave me roughly 1" more clearance and helped me clear the brake lines. Almost looks factory.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Your truck is looking amazing. What size tires did you put on?

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Thanks for the encouragement. I ended up going with Firestone Destination LT33x12.50rx15 tires. I obviously haven't drove on them yet, but think they have a good aggressive look and with the tread pattern I wont have to much road noise while driving. I was on the fence between these and BF Goodrich. I see a lot of guys running the BF tires on their trucks, but have had good luck with Firestones in the past- plus they were roughly $200 cheaper for the set of four.

Re: Winging a 1971 K5 Blazer L96 6L90 Swap
 

Made very small steps forward today. Ended up getting some heat shield protective boots for the plugs. The wires sit pretty tight against the shorty headers.

Quick question for guys that have done builds in the past. Has anyone had the exhaust system built without having the body on the frame? Just worried about clearance issues if I have this done without the body on. All input is welcome.

Thanks,
Andy