mrmotley

Purchased a montero from a friend planning a new home for my 8.1 liter 496. This tall deck block of 10.2 with cathedral cast iron heads share similarities of the lsx family of engines. Considering it's a torque monster that lacks a pcm tune I decided a foreign truck that size with a GM power plant would not only be awesome yet down right disrespectful. Can you imagine sitting at a traffic lit on a hot summer day window down with the sound of a angry big block in suv with people sitting next to you looking confused? The light turns green and you chirp the wheels. Then you purposely go to the oil change place and they pop the hood and say; what the % $&* is this? lol. Anyway I get that with my envoy pulling away from a trailblazer ss or when I pull into a gas station. ...lol. My plan is simple the 496 year 2001 -2007 has a 24x crank triger like the lm4, lm7, lq4 and early ls2. The drive by wire throttle bod y can be swap out with the cable throttle body from the early lsx truck engines.you can swap the crank sensor, and cam sensor plugs as well throttle position to work with the standard ls or truck harness. You can also use the marine harness its already stand alone plug a start for boat application. Back to the 24x reluctor, yes you guessed it 6010 msd. Your next question is what about intake? Dart makes an intake it sell for $565. Another option is distributor. The 496 has a block off plate of some sort in the engine once you remove the factory intake. Now what cam would you use? You can use the zz454, 572, 503 or has comp custom grind one for the 3 I just mentioned and slap it in, drop the same distributor from either add fuel and play. The 496 has flat top pistons with exhaust valve relief. Forged rods, hyper coated aluminun pistons, the stock cam is small and specked for huge low end torque. Crank cast internally balanced. trans wise im going with my favorite 4l80e. I'll upload pics soon thanks for reading.

mrmotley

Heres pictures of the truck.

mrmotley

Today I was cleaning the engine up and saw the block casting numbers 12558110, and crank cast 430. I ran the numbers through A GM sight as well a good friend who works for gm. I foubd out the 8.1 I hve is a 2001-early 2002 496 HO engine. Now the difference is this engine has forged internals, except the pistons. Some of you may say oh your 8 should be a 6 in the casting numbers. Well you're wrong. Anyway on a budget build ill upgrade the cam and valve train plus port the stock heads and see how she growls. She ready for paint now here's some pics. Thanks for reading more to come.

i r teh noobz

iTrader: (4)

Interested. There aren't many 8.1 swaps around. I'd like to see how it performs.

bczee

iTrader: (12)

them 8.1l are out there.. but not too many High Performance options and parts. some but not many.. but if your looking for Torque... you got that right. !

Keep us posted.. !

BC

mrmotley

I thought the same. I've done lots of 6.0 lq9/lq4 and they are mad with a valve train and cam swap. From my research the 572 heads will fit you'll have to have a sheet metal intake custom made. I should have taking a pic when I put my buddies 572 heads on it. He took them home before I could put money on the table. You can bore the 8.1 and use the 572 pistons as well. You can actually do more than you think with these engines. For now ill just do the basics.

murphinator

iTrader: (2)

I was in the boat business for years , plenty of 8.1 mod options on the marine end check out Raylar they had some nice stuff and knowledgeable staff that i remember speaking with at boat shows.

mrmotley

I was on their web page and the had lots of parts as well. I aim leaning in that direction. I decided yesterday to get the Dart intake and msd 6010 and run it that way.

mrmotley

While waiting for parts I ordered decided to add some color.

98TA6.0

iTrader: (42)

Lol you didn't mask the timing set or gasket sealing surface.

A.R. Shale Targa

iTrader: (2)

I'm not too sure you could bore that block from 4.250" out to 4.560" without
ending up with brutally thin cylinder walls but that 4.375" crank definitely
looks forged to me. Coupled with those heads should really wake up with
some cam timing. I'd love to do a Borg Warner S480 blo-through on one of
these someday...that intake looks pretty cool too. BTW those heads are call-
ed the L29 vortecs correct ????

mrmotley

Right lol..

mrmotley

I actually have theBORG WARNER S475. the 8.1 has the big block bolt pattern and cast iron. The difference between the 8.1 496 heads and the traditional big bloxk head are they're cathedral port heads. I wont bore it I want to make very little changes to see what I get.

mrmotley

For those who have the 8.1 496 2001-2007 with the cam baring part number 12556291 the spevs are .476/459 117 lsa

mrmotley

Stock cam with removable gear for camshaft install.