8.1 VORTEC SWAP

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Jan 19, 2005
Threads
191
Messages
4,368
Location
South west utah
I AM CURRENTLY PLANNING AN ENGINE SWAP FOR THE OLD GIRL. I KNOW PLENTY OF PEOPLE HAVE STABBED THE 5.3 AND 6.0 VORTEC ENGINES IN, BUT I HAVE NEVER SEEN OR HEARD OF THE 8.1 VORTEC BEING USED. HAS ANYBODY SEEN OR HEARD OF THIS SWAP. I AM CONSIDERING THE 8.1 BECAUSE I FOUND A DONOR SUBURBAN FOR REALLY REALLY CHEAP WITH A LOW MILEAGE 8.1 AND 4L80E. THANKS
 
Make sure your laws allow you to use a "heavy duty" drivetrain. I'm guessing that 8.1 came out of a 2500 'burb. I've read that in CO, you can run into trouble using the drivetrain from a 3/4 or 1 ton truck in a "light duty" application (80 series is considered light duty).
 
Will it even FIT ??????:hmm:
 
8200 GVW is the cut off for heavy duty/light duty, or somewhere around there. But, I don't think southern utah does emissions. IF same motor is in light duty trucks, colorado MAY look past it IF emissions controls are the same. Consult a mitchell guide. Roll the dice.

I'd be concerned about exhaust fitting between frames. a/c tensioner hitting cross member, will you be able to clear the hood? power steering pump/steering box getting in the way will be a major problem. Also, not sure how long the big block is....4l80e will put the block 1" or so closer to firewall, which will help.
 
COOL IDEA, BRO. LS SWAPS AREN'T EXACTLY MY THING, BUT I HOPE IT WORKS OUT FOR YOU. ALSO, I LIKE YOUR SCREEN NAME, I WAS A BIG FAN OF LEONARD NEMOY AND HIS TV SHOW ABOUT LOOKING FOR SASQUATCH. I DONT BELIEVE IN SASQUATCH PERSONALLY, BUT I FOUND THE SHOW ENTERTAINING. ANYWAY, GOOD LUCK.
 
It will probably fit (maybe) but it will require some reworking. The 454 (the 496 is just a stroked 454) is a lot deeper and wider than the SBC. Mostly Im interested to see how the running gear holds up. I know the 4L80e is up to the task (we had a supercharged Vortec 7400 with the 4l80e that went the distance), but I'm not sure about the A442. You would need to go full GM back to the T-case at least to be sure.
 
i would just go 6.0 and do some mods. there is no way you need the 8.1 in a cruiser. i know my LS1 made over 400RWHP NA and over 550 on the bottle through a TH350 and strange 12 bolt in my camaro.
 
Cant drive the 6.0 flat out without going over the speed limit in the blink of an eye anyway.
We use the all alloy version in Aus
 
Guys have successfully done BB in 40, 45, and 60 in the past, making an 80 series next in line. Steering box might need some attention but Im sure you were anticipating some challenges along the way. If the burb was 4wd I would use the tcase also getting a ~2.73 low range for free. Get to save some dollars not needing any adapters.
 
Guys have successfully done BB in 40, 45, and 60 in the past, making an 80 series next in line. Steering box might need some attention but Im sure you were anticipating some challenges along the way. If the burb was 4wd I would use the tcase also getting a ~2.73 low range for free. Get to save some dollars not needing any adapters.
Except you also get that crummy thermocoupled actuator for 4wd
 
Except you also get that crummy thermocoupled actuator for 4wd

Ya Im not up to date on new stuff. Back in the day when I did our 60 series GM t-cases had manual linkage and women had bushes.:grinpimp:
 
Ya Im not up to date on new stuff. Back in the day when I did our 60 series GM t-cases had manual linkage and women had bushes.:grinpimp:
Anything with the 8.1 will have a tcase that's actuated with a thermal switch...and it's garbage
 
The 8.1 is a dog compared to the 5.3 or 6.0.. that's why you don't see many people swapping them... there is NO advantage to running a 8.1 over a 6.0....
 
The 8.1 is a dog compared to the 5.3 or 6.0.. that's why you don't see many people swapping them... there is NO advantage to running a 8.1 over a 6.0....

can you explain more on this, is this a power to weight issue?
 
can you explain more on this, is this a power to weight issue?

The Advantage of the big block is that its got old school cubes on its side to shift the power curve down and make a high average power rating with low engine stress. Its a lot like the mantra of the cruiser engines generally, but...they are really heavy engines, don't rev worth a darn to generate peak power (without a lot of work) also like the cruiser engines. The Small blocks do rev, they are light and they still make a lot more power than a cruiser needs even down low. They wont be AS robust as a big block, but its marginal at best. The trade off with the sbc over the big block is that its a MUCH more fuel efficient engine, while making the same or more power.
 
The Advantage of the big block is that its got old school cubes on its side to shift the power curve down and make a high average power rating with low engine stress. Its a lot like the mantra of the cruiser engines generally, but...they are really heavy engines, don't rev worth a darn to generate peak power (without a lot of work) also like the cruiser engines. The Small blocks do rev, they are light and they still make a lot more power than a cruiser needs even down low. They wont be AS robust as a big block, but its marginal at best. The trade off with the sbc over the big block is that its a MUCH more fuel efficient engine, while making the same or more power.

agreed... the pros FAR outweigh the cons when it comes to the 5.3 or 6.0.. plus you wouldn't be going into uncharted territory with the swap...unless you just wanted to... :)
 
Ya Im not up to date on new stuff. Back in the day when I did our 60 series GM t-cases had manual linkage and women had bushes.:grinpimp:

My monitor nearly got the coffee spray treatment when I read this!
 

Users who are viewing this thread

Back
Top Bottom