H55F vs NV4500 (1 Viewer)

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Kirkade

SILVER Star
Joined
Feb 9, 2021
Threads
6
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32
Location
Salt lake city
Looking for advice for my particular build. I started my Land Cruiser restoration earlier this year. The original engine was scrapped and I accomplish an LS 6.0 swap. Issue I am having is I did not replace the H42 transmission. So now I got a cruiser with an LS that is limited to highway speeds of about 55. My two options are either the H55F or the NV4500.

When I installed the LS I equipped the Marks Adapter and spaced the engine according. For anyone not familiar with this kit it basically adds an additional bell housing between the engine and the transmission. Right now I have about 12” of bell housing between the engine and transmission. So I think switching the NV4500 is going to have major spacing issues, as I will lose 6” of bell housing, with the shifter unless anyone has any suggestions.

If I go with the H55F Transmission I can keep the Marks kit but I am having reservations about The LS Torque destroying the trans. On paper I should be pushing about 432 lbs at the tranny. And there is a sever lack of information on the H55F.

I should note that I restored this Land Cruiser to be a family car / show rig and not a trial rig. So 1st gear ratio’s discussions are pointless for me but the overdrive reduction of the NV4500 .77 vs the H55F .845 is attractive. But as a show car and for collectors value I wonder if the H55F transmission has a greater value then a NV4500.

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I have the same Mark's kit to an H55, but it's on a 5.3 EROD motor. But my understanding is they're plenty strong. I'm probably a good 100hp/100ft lbs lower than you are, mind you. Certainly it has no prob getting well into highway speeds I don't particularly feel too comfortable driving a 35 year old 4x4 at. I think most folks just like the Chevy transmission for it's gearing and that the Mark's kit can have some issues with slippage. But either way, you're still dealing with an adapter somewhere. Thus far though (knock on wood), the Mark's kit seems to work pretty nicely.
 
I'm preppin for a LS3 swap and recently asked very similar questions. @torfab mentioned the H55 with the Marks will be just fine as it has worked on several swaps.
 
With the way you did the swap just stay with tge toyota transmission h55. Whats up with the Holley sniper on the ls why that route over the oem ecm and oem components? How did you come up with the hp raiting engine work done?
 
yeah do a H55f. It will be an easy bolt in. If you have the stock 3.70 gears it should be plenty of highway gearing with the 33” tires. As for strength/ longevity you will hurt axles/spider gears/crosspins/hub studs way before the transmission.
 
With the way you did the swap just stay with tge toyota transmission h55. Whats up with the Holley sniper on the ls why that route over the oem ecm and oem components? How did you come up with the hp raiting engine work done?

sniper and a mallory box, all that effort and money to have inferior EFI :lol:
 
Well originally I was going to run a Holley Avenger Carburetor on the LS engine and a manual transmission so I got rid of the ECM, intake and tranny. I was planning on using a MSD box which is easier for me to tune. As projects normally do it expanded as I found these FJ60s use a manual fuel pump and my in line electric Holley pump wasn’t pulling reliable fuel pressure. So I dropped the tank to add an a fuel pump inside the tank and ran new high pressure lines. Then as I had sold the extra LS parts I traded the two carbs I had for a Holley EFI.

As for the engine, I built it before I had the Land Cruiser as a home school project for my son last winter. We added a more aggressive crank, rods and used 706 heads. Modified the oil intake and oil cooler ports. Exhaust is 2 inch until the Y and then 2 1/2 the rest back.

I have haven’t dino’ed this particular engine but I have on others with this build and they are around 400 hp and 432 torque.
 
H55f will be a one day project for you.
 
I have a fj40 with a nv4500 and just picked up a 87 fj60 with a h55f ram jet 350. No comparison the h55f is smoother to shift and quieter. BTW i am in slc utah if you wanna take it for a spin
 
I have a fj40 with a nv4500 and just picked up a 87 fj60 with a h55f ram jet 350. No comparison the h55f is smoother to shift and quieter. BTW i am in slc utah if you wanna take it for a spin
That would be fantastic and very appreciated
 
I have a 60 with 5.3 and NV4500, I drive the vehicle all the time with 33’s on and off road, it is very confidence inspiring. I never worry about overloading anything because it was built to take the abuse. It is no problem to cruise at 75-80mph all day and have done it on long trips many times. If I do this again I ll go with the 6.0 and NV4500. More power is more better.
 
If you've already got the marks adapter stuff, I'd go H55. NV4500 is nice for the extra low 1st if you get the older one, but you've got to buy the new adapters in addition to the NV4500. Also as a side note, I've got an NV4500 behind my LS and I've been fighting clutch issues ever since I got it running. Trying to save a few bucks and not get the AA flywheel/clutch kit has cost me more that it would've originally so if you do go NV4500, just buy the stuff that is made for it in the first place lol.
 
If you've already got the marks adapter stuff, I'd go H55. NV4500 is nice for the extra low 1st if you get the older one, but you've got to buy the new adapters in addition to the NV4500. Also as a side note, I've got an NV4500 behind my LS and I've been fighting clutch issues ever since I got it running. Trying to save a few bucks and not get the AA flywheel/clutch kit has cost me more that it would've originally so if you do go NV4500, just buy the stuff that is made for it in the first place lol.
AA sticks it to ya on the clutch stuff that they say specific made for their conversion kit luk clutch centerforce pressure plate can't remember the flywheel manufacturer and a fj60 throw out bearing things you shouldn't have to pay 1000 dollars for through them it may be more now this was about 8 years ago.
Tommy
 
I also run the 5.3L/NV4500/33" tires and I love it. I initially had the H55 when the truck was first converted and I had many clutch issues; rattling clutch at idle, front tranny retainer broke 2X and the 2nd time the retainer broke, the clutch was broken in pieces. Mark Algazy was the one who spotted the broken retainer the first time it happened at the LSLC Roundup several years ago. It turned out that the mechanic that did the conversion used the wrong AA adapter , he used 4 speed instead of the 5 speed (Marks) adapter. Sold the H55 & ended up buying the NV4500 cause I liked the idea of mating the chevy motor to chevy tranny. Got the AA NV4500/Toy split case adapter and have not had any issues. I kept the Downey flywheel and orderd the Luk clutch kit from Summit Racing for about $200
 
So I have 1983 FJ60 with 5.3l vortec and H55f trans. been driving it for about 2 years but suddenly on a trip to AZ and UT the clutch when hot started not releasing fully making shifting near impossible I used the following adapters stuff:

Clutch Kit:
Clutch Kit (Organic Plate) - Chev V8 Petrol 12" - 10 Tooth Spline | Marks4WD - https://www.marks4wd.com/mck110.html

Fly Wheel Kit:
Flywheel - LS Series V8 Engines (Heavy Duty) | Marks4WD - https://www.marks4wd.com/mfk268g3.html

Bell Housing Adapter kit:
Bell Housing Adaptor Kit - LS Series V8 to LandCruiser FJ Petrol (Manual) | Marks4WD - https://www.marks4wd.com/mfk560g3.html

My rig is presently at Tip Top Transmission in SLC getting looked at so don't know bottom line problem yet but looks like thrust bearing or shaft is jamming when hot. I put in new master and slave when issue started happening as I thought one or the other had gone bad but that didn't fix the issue.

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So I decided to do the H55F swap. I am about halfway through the swap. Had issues sourcing new transfer-case to transmission bolts. Ended up having to get some made. So if anyone needs some I have extra now. Also noticed my Engine snapped the H42 transmission input shaft in half. So I am a little worried that the H55F maybe a bit weak.
I will add a write up of issues with pics after I am done.
 
No way you snapped a input shaft.

Making custom bolts sounds like a lot of effort compared to getting them from Toyota for about $5 each
 
Yeah, my toyota dealership told me the part number has been discontinued. And online there was none available. I managed to find one bolt used on ebay, that I used for fit: size, thread and dimensions. And after a month of searching the only option I had was to get them custom made. Yes big hassle.
 
Will have to take a pic of the broken input shaft tomorrow when it is light outside. Its 27 and dark right now so not taking any pics.
 
Will have to take a pic of the broken input shaft tomorrow when it is light outside. Its 27 and dark right now so not taking any pics.

If you really did sheer an input shaft that is a freak material defect. Transmission input shaft sees the lowest torque engine drivetrain. And if you were having reservations of strength issues compared a NV4500, the GM NV4500 input shaft is the same size.
 

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