8.1L....will it fit?

[ssapach]

I've been told that an 8100 vortec will fit with ease under the hood of my 1986 GMC.

Now, simply fitting under the hood is one thing, but there are a few more considerations:
-will the oil pan clear my front differential with stock suspension?
-will it fit between the frame rails?
-will the motor mounts bolt up to where the current 454 sits?
-will there be any interference with the passenger side head/valve cover/exhaust and the HVAC box on the firewall?  (truck is equipped with a/c)

I'm curious because I discovered an 8.1 for sale close to home.  Seller is asking $1000 and it comes as a complete motor, all accessories, wiring and ECM and has about 205 000 km on it.

Any help or suggestions would be appreciated.  When I'm home I might try to drive out and have a look at the beast.

[1980c10]

I don't have an answer but you should give some more info about your truck auch as 2wd or 4wd or any other info that might be helpful.

[1979C20]

I don't have an answer but you should give some more info about your truck auch as 2wd or 4wd or any other info that might be helpful.

I've been told that an 8100 vortec will fit with ease under the hood of my 1986 GMC.

Now, simply fitting under the hood is one thing, but there are a few more considerations:
-will the oil pan clear my front differential with stock suspension?
-will it fit between the frame rails?
-will the motor mounts bolt up to where the current 454 sits?
-will there be any interference with the passenger side head/valve cover/exhaust and the HVAC box on the firewall?  (truck is equipped with a/c)

I'm curious because I discovered an 8.1 for sale close to home.  Seller is asking $1000 and it comes as a complete motor, all accessories, wiring and ECM and has about 205 000 km on it.

Any help or suggestions would be appreciated.  When I'm home I might try to drive out and have a look at the beast.

I don't have an answer but you should give some more info about your truck auch as 2wd or 4wd or any other info that might be helpful.

1986 GMC 4x4 stock height with a 454 and ac. Not too much more you need to know.

[Irish_Alley]

whats the vin and your ss#?

[Irish_Alley]

not sure but what year is the 8100v tec. will it mate to currant transmission?

[ssapach]

The 8100 is out of a 2002, which happens to be the very year of truck my transmission came out of.

My understanding was that it would even have the same bellhousing bolt pattern as the 454/SM465 currently in the old truck.

[1980c10]

I didn't need to know any of that as i don't have the answer, however more information will get faster answers.

[1979C20]

If people are talking about shoehorning one into a firebird, i bet it will fit in our truck. Especially since you already have a big block.
http://www.thirdgen.org/techboard/engine-swap/471013-8-1-vortec-swap.html

[1979C20]

http://www.youtube.com/watch?v=5LhzgJUMjCs&feature=youtube_gdata_player
done/doable. But apparently you have to notch the crap out of the frame for ac unless you buy a bracket to raise it on the engine.

[big bear]

thats sick.  i love the 8.1

[ssapach]

I think I should go have a look at the motor first, make sure it comes with everything I'm expecting it to and make sure it's not covered in oil.

Thanks for the input everyone.

That video is even more inspiring too.....that engine would look at home under the hood of my truck.

[Captkaos]

little info here:
http://forum.73-87chevytrucks.com/smforum/index.php?topic=9192.0

[nucknoel89]

Here's a step by step, it's for an 88 but it's acrew cab so the same style as 73-87s.
http://www.hotrodlane.cc/Streetstories/81%20swap.pdf

[ssapach]

Thanks for the links guys.

All that frame notching and reinforcing scares me a little.  Not so much that I'm incapable of doing it, but it's more work than I need for what the truck will be used for.

[1979C20]

You dont have to notch it. You could either run no ac, or there are after market brackets that move the ac pump higher on the engine.