What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Which Way Should I Go?

Upstate

Upstate

1/2 ton status
- In Memoriam -
Joined
Aug 16, 2010
Posts
951
Reaction score
32
Location
New York
Been building a '87 K5 for ever now. It has gone through a ton major changes and when I finally start my build thread I will elaborate on its evolution. But for now I am curious about my newest idea.

It currently has a brand new Goodwrench 260hp 4 bolt 350. It has a MSD Atomic for the fuel injection sitting in the box waiting to be used. I broke it in with a Edlebrock carb.

I am thinking about occasionally using it for towing my enclosed trailer. With that going forward I think the 350 will be under powered. I am running a NV 4500, NP 205, 14 bolt with 4.56 and Dana 60. All this is running on Toyo MT 37".


So, I am considering going the LS direction. The question is 8.1, 6.0, or 5.3. Been in contact with Pacific Feb about it and would like to hear your thoughts.
 
24' plus V nose making it 30' overall. 8.5 wide x 6.5 high. 4500lbs empty. My '14 6.0 in stock 360hp struggles a little with highway speeds. Of course my '14 crew cab 2500 does weight 1500lbs more
 
The crew cab will tow better than the blazer regardless of what motor you have in the blazer.
 
skunked said:
The crew cab will tow better than the blazer regardless of what motor you have in the blazer.
Click to expand...

I have a crew cab also. This would towing to local shows. The crew would be for road trips.

How about this, forget towing, which would you for your toy?
 
Forget towing that trailer with the Blazer. The short wheelbase, tires/lift, and lighter weight and less power all work against you. I'd save the crew cab for towing rather than try to make the Blazer into something that it will never be good at.

The 6.0 will be cheaper/easier to find. As previously stated there is a lot more aftermarket support. Some people do like that instant big block torque though, and since the 8.1 is based off traditional BBC architecture, it bolts in a bit easier than an LS motor.
 
paratrooper307 said:
Forget towing that trailer with the Blazer. The short wheelbase, tires/lift, and lighter weight and less power all work against you. I'd save the crew cab for towing rather than try to make the Blazer into something that it will never be good at.

The 6.0 will be cheaper/easier to find. As previously stated there is a lot more aftermarket support. Some people do like that instant big block torque though, and since the 8.1 is based off traditional BBC architecture, it bolts in a bit easier than an LS motor.
Click to expand...

That is one of the reasons I like the 8.1 is the exhaust for example is old school.
 
Dude pm Josh ( 208motorsports) look at rjfguitar thread. He is not the only one I have heard having tuning issues with pac fab.

He just finished up an 8.1 swap in a crew cab dually too. Has done a couple of 6.0 swaps into squares so he could tell ya what's gonna work the best.

He will tell ya straight up what he thinks.

It's well worth it talking to him
 
He has a vid of the 8.1 firing up on his Facebook.

Along with several other cool vids

208 motorsports on facebook
 
I don't do Facebook, have to get the wife involved. I give a shout though. Thanks :waytogo:
 
I have started to keep a second photo gallery for forums.


8.1 Test fire, running open loop, no O2s hooked up, Thorley Tri-Y headers for same body style 454. There is some wires just jumped to test fire. You can also see its all the radiator/ shroud assembly from the square body and mechanical fan. Click pic for video



Only thing we had to notch was the frame for the AC comp.

154555_372554529598307_8265996779611035098_n-L.jpg


19606_373182396202187_4304095029144787145_n-L.jpg


This was also a 2wd so no crossmember mod needed. Even then its not too hard. I have another square body to do, its mine, that one will get a 6.0 and a turbo or 2.... We have done round bodies as well. Have one in the shop now and one behind it.
 
Last edited:
With all the engines we have done the 8.1 is an overlooked engine that provides an easier to swap package. No using adapter engine mounts, headers can be bought thanks to old design, mechanical fan is easy, and power out of the box is awesome.

The 8.1 with just a good tune is one stout ass engine. We built the 4l80 behind it in the square body so I could tune it all the way. Doing burnouts with a dually is awesome. I'll get that video up once the truck is 100%. As far as aftermarket, you have Raylar. They seem expensive until you price a stroker LS. If you want the best bang for the buck you port the 8.1 intake, run larger injectors and have a real tune built. We are waiting to port the one here due to the owners budget but I am maxing the stock injector on the stock setup. As in over 100% duty cycle...... Not good. On a wideband though its only dropping into the 13s so I am not too worried about it until he can upgrade.

The most important thing on any of these swaps is getting fuel to these engines. If you have a tbi rig now, swapping intank pumps is easy. If you have non baffled older tanks and plan on running external, it has to be setup right. We ended up running a puller pump and a high pressure pusher for the 8.1. The high pressure could not pull when swapped to the second tank. Seems it would lose its prime during the switch. That was taken care of by using a high volume puller, larger filter that T's into return for a surge and high pressure pusher. The awesome thing now is, if the tanks are low and this truck comes drifting around the corner it has a surge setup in the filter....
 
Craving HP and honestly something new, but I am warming up to a nice set a aluminum heads and roller cam.
 
Ended up buying a lower mileage '05 6.0 for my endless pursuit of spending money..
.
.
.
.
.
and '15 LTZ Crew Cab with the Duramax / Allison combo.
 
You must log in or register to reply here.

Latest Posts

Top Bottom