What's new

8.1L/496 Tech

WESTOF7

Fueled by hate and bacon
Joined
Aug 6, 2020
Member Number
2422
Messages
62
Loc
Frozen Wasteland
An 8.1L allison and ZF6 arent remotely comparable. Fuck autos behind these engines. I've settled for a NV4500 as the ZF6 are too much $, due to duramax prices and GMs retardation of no manuals early on.
I feel the same way. I want a manual behind a big block. Kinda want the zf6 never been a fan of the nv4500.

IF I'm getting fucked on the price of fuel to feed the fucking thing I might as well enjoy it with a manual :smokin:
 

blakes

Well-known member
Joined
May 19, 2020
Member Number
205
Messages
109
Loc
Storm Mountain CO
An 8.1L allison and ZF6 arent remotely comparable. Fuck autos behind these engines. I've settled for a NV4500 as the ZF6 are too much $, due to duramax prices and GMs retardation of no manuals early on.
What kind of bellhousing and clutch do you run with an 8.1/nv4500? I have an old 75 GMC c35 that currently has a 4l80e slipping and needs swapped. Thinking about nv4500...
 

Russell

LLY/ZF6 Escalade
Joined
May 21, 2020
Member Number
837
Messages
133
Loc
Rocky View County, AB
The NV4500 came stock behind 8.1L engines in the old body style 2000/2001 HD trucks. The flywheel, pressure plate, pilot bearing etc are the same as all the old school SBC/BBC internally balanced 168 tooth stuff. The OEM flywheel has metric pressure plate bolts and dowel pins for alignment. If you order the factory GM part number for the pressure plate you'll get a Luk SAC clutch cover. They can be a PITA. I decided to go with an old school diaphragm pressure plate with the mounting holes enlarged to fit the metric hardware and drilled for the dowel pins, OEM 8.1L/NV4500 flywheel and a 10 spline clutch disc to fit my transmission's input.

You can use any GM NV4500 bellhousing and an 85-91 square body hydraulic clutch and master to operate either the internal or external slave depending on what year of NV4500 you run. You'll need to make your own hose to connect the two, but the aftermarket has all the fittings needed to put a -3 AN hose between the two. Of course you'll need a high hump transmission tunnel to clear the transmission. You will also need to update the tuning on the engine to suit as well.
 

TRINDU

PBB Orphan
Joined
May 19, 2020
Member Number
386
Messages
2,280
Loc
Central TX
What kind of bellhousing and clutch do you run with an 8.1/nv4500? I have an old 75 GMC c35 that currently has a 4l80e slipping and needs swapped. Thinking about nv4500...

You can buy a brand new 6.0 bell for about $250 shipped. GM is all the same pattern.
 

total newb

senior jerk ass
Joined
May 19, 2020
Member Number
283
Messages
1,358
Loc
trinity center ca
Almost.

Sbc/ bbc and ls are very close. But a ls uses the 7th/ top hole that most sbc/bbc dont even have and do not use the 1-oclock hole.

Only a ls nv4500 bell will have the top bolt hole.

Idk if its that big of a deal but ijs
 

blakes

Well-known member
Joined
May 19, 2020
Member Number
205
Messages
109
Loc
Storm Mountain CO
The NV4500 came stock behind 8.1L engines in the old body style 2000/2001 HD trucks. The flywheel, pressure plate, pilot bearing etc are the same as all the old school SBC/BBC internally balanced 168 tooth stuff. The OEM flywheel has metric pressure plate bolts and dowel pins for alignment. If you order the factory GM part number for the pressure plate you'll get a Luk SAC clutch cover. They can be a PITA. I decided to go with an old school diaphragm pressure plate with the mounting holes enlarged to fit the metric hardware and drilled for the dowel pins, OEM 8.1L/NV4500 flywheel and a 10 spline clutch disc to fit my transmission's input.

You can use any GM NV4500 bellhousing and an 85-91 square body hydraulic clutch and master to operate either the internal or external slave depending on what year of NV4500 you run. You'll need to make your own hose to connect the two, but the aftermarket has all the fittings needed to put a -3 AN hose between the two. Of course you'll need a high hump transmission tunnel to clear the transmission. You will also need to update the tuning on the engine to suit as well.
thanks

I'm starting to really think about doing this swap (along with a front D60) and my concern is the part you said about the 'high hump transmission tunnel'. My truck is a 75 GMC c35 2wd dually that I swapped an 8.1 into a few years ago mated to a gear start 4l80e. Well this mountain that I live on did what the old timers always said it would do: it ate my auto tranny. Been getting a P0894 now for a couple of years. The truck is ONLY used to haul materials and water up here (22" GN with 850 gallons).

I have a J10 with AMC 360/nv4500/atlas 4spd and I really like the nv4500.

I need to educate myself on the tranny hump. Hope that won't be a show stopper to convert my old square.
 

Grendel

Insert something witty in your mind.
Joined
May 19, 2020
Member Number
297
Messages
1,434
thanks

I'm starting to really think about doing this swap (along with a front D60) and my concern is the part you said about the 'high hump transmission tunnel'. My truck is a 75 GMC c35 2wd dually that I swapped an 8.1 into a few years ago mated to a gear start 4l80e. Well this mountain that I live on did what the old timers always said it would do: it ate my auto tranny. Been getting a P0894 now for a couple of years. The truck is ONLY used to haul materials and water up here (22" GN with 850 gallons).

I have a J10 with AMC 360/nv4500/atlas 4spd and I really like the nv4500.

I need to educate myself on the tranny hump. Hope that won't be a show stopper to convert my old square.
It bolts in.
 

blakes

Well-known member
Joined
May 19, 2020
Member Number
205
Messages
109
Loc
Storm Mountain CO
I have a buddy with a '98 chevy 3500 with 6.2 diesel and nv4500. he will give the nv4500 to me for free. I wonder if that bellhousing will work for ? I don't know anything about those chevy diesels.
 

ridenby

Red Skull Member
CAL4
Joined
May 19, 2020
Member Number
183
Messages
511
Loc
Kentucky
I have a buddy with a '98 chevy 3500 with 6.2 diesel and nv4500. he will give the nv4500 to me for free. I wonder if that bellhousing will work for ? I don't know anything about those chevy diesels.
Same bell as SBC/BBC .
This thread has a lot of info on 8.1 Hope yall do not mind.

 
Top