NV4500 swap is underway

[v30crewcab]

I made my own version of the aa bracket. it uses the factory shifter. works great. will have to see if I have any pics of it.

[Chevy3+3]

Originally Posted by v30crewcab

I made my own version of the aa bracket. it uses the factory shifter. works great. will have to see if I have any pics of it.

I would like to see your pics if you can find them. I am wanting to keep my factory shifter when I do my swap.

[jbanks843]

dirty larry sorry to ask such a repeat question ive recently bought an 8.1 and plan on installing in my 97 3500hd that had a 6.5 diesel with a manual 5 sp nv4500, what i gather from reading your build does the swap on require a 8.1 manual flywheel the nv4500 already existing clutch setup or am i interperting it incorrect if so what clutch would i need?

[DirtyLarry]

Originally Posted by jbanks843

dirty larry sorry to ask such a repeat question ive recently bought an 8.1 and plan on installing in my 97 3500hd that had a 6.5 diesel with a manual 5 sp nv4500, what i gather from reading your build does the swap on require a 8.1 manual flywheel the nv4500 already existing clutch setup or am i interperting it incorrect if so what clutch would i need?

Yes, the 8.1L will need its own flywheel. The flywheel bolts pn is 12561465 and the flywheel itself is 12582964. 8.1L’s were used in 2001 and 2002 GMT400 3500-HD trucks so I would use one of those truck models for parts look up to compare part numbers somewhere like Napa or Rock Auto between the clutch/pressure plate for a 6.5L vs. 8.1L. I doubt they are the same clutch and pressure plate.

[jbanks843]

How do i identify the model nv4500 in my 97 to a 01-02 manual if their even the same. Like bellhousing patterns.

[snj8198]

Larry, did you ever swap out your rear Detroit for a selectable?

[DirtyLarry]

Originally Posted by snj8198

Larry, did you ever swap out your rear Detroit for a selectable?

No, not yet. Too many other projects cooking. One of these days tho. Don’t want an ARB but more of an E-locker. Don’t feel like fidding with a compressor and lines. Don’t have much more room under this thing

[rickcdewitt]

larry if you still have that 2003 bellhousing would you consider selling it?

[bilfman]

Hey Larry, I'm considering an 8.1 swap. I have leads on an entire truck and another lead on just motor cpu and harness, which is a better option in your opinion. The motor is a 1/3 less price then truck with motor. Are there many incidentals that are beneficial having the complete truck?

[DirtyLarry]

Originally Posted by bilfman

Hey Larry, I'm considering an 8.1 swap. I have leads on an entire truck and another lead on just motor cpu and harness, which is a better option in your opinion. The motor is a 1/3 less price then truck with motor. Are there many incidentals that are beneficial having the complete truck?

Bilfman,

Personally, I would just go after the engine and ECM. There isn’t anything else from the truck itself that you would really need, including the harness. I would not bother with a donor harness from a truck. The best $500-$700 you can spend on a swap like this is starting with a brand new fresh stand-alone harness from one of many harness vendors. Howell has a decent harness although their consistency seems to a moving target as both my K10 and Suburban harnesses were ordered alike but showed up completely different (trunk lengths, etc.). On the other hand, Howell does have a nice ECM tune for the 8.1L with or without electronic throttle. I use 96-00 L29 7.4L mechanical throttle bodies on both of mine.

If you haven’t already, read through THIS thread. I created it to help 8.1L swappers with the basics and slow down on the PM and highjack traffic.

[bilfman]

Awesome thanx for the info, i'll keep the forums posted once the build begins.

[binnsmark]

As I read your entertaining and informative threads... I start to forget the information I read earlier. That being said... I recently purchased an 8.1 out of an 04 (maybe 05, have to drive a few hours to get it) with an Allison 1000. I want to ditch the Allison in favor of an NV4500. I'm more interested in getting the later 5.61 1st gear anyway (95 and up.)

Are there any adaptabilty differences to the 8.1 between the earlier GM NV4500 and the later ones?

Thanks very much in advance!

[DirtyLarry]

Originally Posted by binnsmark

As I read your entertaining and informative threads... I start to forget the information I read earlier. That being said... I recently purchased an 8.1 out of an 04 (maybe 05, have to drive a few hours to get it) with an Allison 1000. I want to ditch the Allison in favor of an NV4500. I'm more interested in getting the later 5.61 1st gear anyway (95 and up.)

Are there any adaptabilty differences to the 8.1 between the earlier GM NV4500 and the later ones?

Thanks very much in advance!

From what I can tell, the early NV4500 will bolt up but you will need to use an early GM NV4500 bell too which brings up another bag of worms with the slave being on the passengers side. I don’t believe the AA bell that I am using will work with an early NV4500 as their site says 96 and up.

[binnsmark]

Originally Posted by DirtyLarry

From what I can tell, the early NV4500 will bolt up but you will need to use an early GM NV4500 bell too which brings up another bag of worms with the slave being on the passengers side. I don’t believe the AA bell that I am using will work with an early NV4500 as their site says 96 and up.

Oh man this stuff makes me scratch my head.

Thank You!

[argonaut]

AA makes bellhousings for both early and late GM NV4500s. PN 712577 is for 93-95 transmissions and PN 712576 is fit 96 and up. Neither of them are cheap.

[binnsmark]

Originally Posted by argonaut

AA makes bellhousings for both early and late GM NV4500s. PN 712577 is for 93-95 transmissions and PN 712576 is fit 96 and up. Neither of them are cheap.

I've seen these. And I appreciate it. Just trying to figure out which transmission I should go for. Are they all internal slaves? In Larry's previous post he mentioned about slave being on the passenger side. Is this internal on the pass side or external?

[argonaut]

93-95 are all external slaves. 96 and up are the unitized slave-bearing.

[argonaut]

93-94 have the low first gear. 95+ have the higher first gear.
93-95 share the same bellhousing bolt pattern. 96+ is different.
So 95 is the year to get if you want to use the factory GM bellhousing with the higher gearing.
if you are just going to use an aftermarket bellhousing then it really doesn't matter.

Make sense?

[binnsmark]

Originally Posted by argonaut

93-94 have the low first gear. 95+ have the higher first gear.
93-95 share the same bellhousing bolt pattern. 96+ is different.
So 95 is the year to get if you want to use the factory GM bellhousing with the higher gearing.
if you are just going to use an aftermarket bellhousing then it really doesn't matter.

Make sense?

Thank you. Much more sense. 95 has the 1st gear I want and an external slave. Thank you.

In your wisdom, do you recommend utilizing an internal or external slave? I realize if the internal slave fails I have to take out the transmission, but is plumbing a set up for an external slave any harder? The ol' SM465 in mine has a mech linkage so I will have to retrofit.

I'm not new to wrenching but I am new to swapping around parts from different years and going from a carb'd straight 6 to an EFI BB. Your knowledge sharing isn't being wasted and I appreciate your time.

[argonaut]

Well as Larry was saying the only problem with using a factory 93-95 bellhousing with external slave is that the slave is located low on the passenger side. In the 90's the trucks switched to drivers side front driveshaft. So its a bit of a conflict having the front driveshaft on the passenger side and the slave cylinder on the passenger side because it sits kind of low on the bellhousing. If you have a god size lift and a not too flexible suspension perhaps it isn't a problem.

The plumbing isn't really any harder. You can use the factory master, line and slave cylinder. They use a unique clip type fittings. But you can buy an adapter fitting made by Russell, or similar, from Summitracing that will convert that to -AN size, in the case that you want to make a custom line or convert and use a different master cylinder.

[argonaut]

Some people have said that the internal slaves have a bad reputation of failing, and then obviously they are a pain to replace. But it sure would make the installation a lot cleaner.

[binnsmark]

Thanks very much and I'll take it into consideration. I wonder if they really do have a high failure rate or if it's just the face that the are a PITA to install. Thanks for the time.

[DirtyLarry]

Argonaut hit the nail on the head with the pass side vs. driver side slaves. Regarding the internal slave/release bearing assemblies used on the 96 and later transmissions, I feel those would be harder to install into older trucks as the transmission and bellhousing must be bolted to the engine in one assembly opposed to bolting up the bell first then bolting the transmission to the bell. My K10 and Suburban would virtually be impossible to shove the transmission and bell up already bolted together up to the engine at the same time because the 8.1L engines will not tilt down far enough. An automatic has a smaller trans body where the bell can be snuck up under the floor and past the firewall. A big NV4500, not so much. Just my .02 about using an internal slave on an older rig

[binnsmark]

Originally Posted by DirtyLarry

Argonaut hit the nail on the head with the pass side vs. driver side slaves. Regarding the internal slave/release bearing assemblies used on the 96 and later transmissions, I feel those would be harder to install into older trucks as the transmission and bellhousing must be bolted to the engine in one assembly opposed to bolting up the bell first then bolting the transmission to the bell. My K10 and Suburban would virtually be impossible to shove the transmission and bell up already bolted together up to the engine at the same time because the 8.1L engines will not tilt down far enough. An automatic has a smaller trans body where the bell can be snuck up under the floor and past the firewall. A big NV4500, not so much. Just my .02 about using an internal slave on an older rig

Hey, thanks for the replies! So, am I correct in assuming that there are no external slave GM NV4500's with the slave on the drivers side? Or would it only be 1992?

[DirtyLarry]

Nope, hence the reason I'm using Advance Adapter bells on my rigs instead of a factory GM bell of any sorts