DERTY

Anyone know what it would take to swap a 8.1 into a 1500 Silverado Z71? It currently has the 5.3. I just got the truck and can get a 8.1 for cheap. I was just curious if anyone has any ideas if it would work, would require some serious changes, etc. Any ideas?

GREGGO

iTrader: (2)

That is a totaly different engine than the LS1 based motors like the 4.8,5.3, and 6.0. You would have to buy most of your parts specifically for an 8.1. A 6.0 would be a much easier swap, and the parts are more availiable. Look up Gandolphxx and Tbyrne , they both have 8.1's that run pretty damn good. They are both in heavy trucks and are blown though. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

CMNTMXR57

Also, the 8.1 would add a lot of unsprung weight to your front end as the engine itself probably weighs twice as much as a 5.3. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Then you have to factor transmissions in. You couldn't just bolt up your 4L60E and expect it to last very long. In which case you'd be limited to three trans choices. A 4L80/85E from an Avalanche 2500 (that had an 8.1), or either the 6 speed manual or Allison 5 speed auto.

Of the later two, I think both aside also from the weight factor, are too large to fit in your tunnel and in the case of the Allison, it really isn't a performance oriented transmission. It's kinda a boat anchor in these terms. It does it's best with a BIG trailer out back. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

So your only real option is a 4L80/85E. Interesting swap, I'd like to see someone do it. I even contemplated getting a cheapo 4th gen F-Body and dropping the 496 into it.

MiSdIrEcTeD_1

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Fast4.8:
<strong>A 6.0 would be a much easier swap, and the parts are more availiable. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">If I were gonna do a swap Id also go with the 6.0... Much easier to do and like Fast4.8 said, Parts are cheaper to come by... <img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" />

99GMC Can

The 6 spd has nice gear ratios, but it would take a good arm to throw that stick around. With the 4x you would need to swap the transfer case too. The 8.1 pushes over 500lbs torque before mods

CMNT* unsprung weight has nothing to do with the weight of your motor, unless you have no suspension.

"There's no replacement for displacement"

CashDudeHomie

iTrader: (5)

I read an article about the first guy to ever do the swap. To put an 8.1 on the 1500 chassis, you have to body drop the nose at least 3 or 4 inches where the engine mounts are (the HDs apparently come with a body lift.) It would be fun and yeah lots of displacement, almost 500 ci, but I think the 422 would be much more practical.

really slow truck

LMAO! u KNOW its not worth it when peeps talkin bout a 422 being more practical! <img border="0" alt="[jester]" title="" src="graemlins/gr_jest.gif" />

DERTY

I never said anything about practical, but then again it sounds like a ton of work just to fit that in there. Might have to look at a 6.0 with a whipple instead!!

Thanks for the info!

CMNTMXR57

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 99GMC Can:
<strong>The 6 spd has nice gear ratios, but it would take a good arm to throw that stick around. With the 4x you would need to swap the transfer case too. The 8.1 pushes over 500lbs torque before mods

CMNT* unsprung weight has nothing to do with the weight of your motor, unless you have no suspension.

"There's no replacement for displacement"</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I was more or less referring to the point that say for example a Vortec 6000 weighs 500lbs (hypothetical) and a Vortec 8100 weighs 900lbs (hypothetical) that would add an extra 400 lbs of mass to have to move.

Do you disagree with that? Weight is weight whether it be sprung or unsprung and I think you knew what I meant.

99GMC Can

I ment no disrespect. you're right of course, the less weight the better. Easy to move, easier to stop.