FJ60 LS Swap - From Oil Burner to Gas V8 - Stoffregen Motorsports

[Stoffregen Motorsports]

The stock steering box had a little clunk in it and the customer gave me the go ahead to replace it. Searching around, I found out that the FJ80 box had quicker gears in it, which would make this truck nicer to drive on the road. I found a couple reman boxes online, but they were rediculously expensive, so on a whim, I called around to my local yards and found one, a rebuilt one, for $480, including core charge. I couldn't get the P/S system to bleed, so after thinking about it for a while, I decided that the hose routing was too high, in comparison with the P/S pump reservoir. I shortened the return nipple and dropped the height of all the hoses to just below the fluid level. Seems to have worked. And the box does make it nicer to drive around town.

 

[Stoffregen Motorsports]

Another detail item was the small death wobble. It occurred very rarely, but even rarely is too often. After confirming that the joints and bushings were all tight, and the toe and tire pressure were good, I took a measurement off the knuckle and it only had 2.5 degrees of caster. Replacing the 6 degree shims with new 4 degree shims solved the problem.

 

[Stoffregen Motorsports]

Drive Time

My friend Harry called and wanted to go for a drive, to grab a few pics. He lives about an hour and a half from me so we met in the middle in Colfax, then headed out to the old town of Iowa Hill, then turned south to Yankee Jim's. It was snowing when we left Colfax, and the sun wasn't shining, but just as we got into the cool part of the drive, the sun poked out for a bit. It was a fun drive, the truck did its job without any hiccups, and we got some nice shots.

Here are a couple that Harry was nice enough to share with us.









The man himself...

 

[Upland80]

Sweet rig!

 

[NCFJ]

Nice looking truck Matt. I stick with the stock 4.11 gears on the 62. With a 4L65E it leaves the ratio pretty much right between a stock Silverado 1500 and an HD 2500. This is with 33" tires.

 

[borison]

My friend Harry called and wanted to go for a drive, to grab a few pics. He lives about an hour and a half from me so we met in the middle in Colfax, then headed out to the old town of Iowa Hill, then turned south to Yankee Jim's. It was snowing when we left Colfax, and the sun wasn't shining, but just as we got into the cool part of the drive, the sun poked out for a bit. It was a fun drive, the truck did its job without any hiccups, and we got some nice shots.

Here are a couple that Harry was nice enough to share with us.









The man himself...

Sooooooo much FJ porn there. Gonna need a cigarette.

 

[Stoffregen Motorsports]

Nice looking truck Matt. I stick with the stock 4.11 gears on the 62. With a 4L65E it leaves the ratio pretty much right between a stock Silverado 1500 and an HD 2500. This is with 33" tires.

Thanks Stan. That's what I figured. The 4L60E has a .70 overdrive, and the H55F has a .85 overdrive. Using a calculator, the difference between the 4L60E with 33's and the H55F with 34's is about 400 RPM. With the taller tires on this rig, it may just work out.

 

[Stoffregen Motorsports]

Sooooooo much FJ porn there. Gonna need a cigarette.

I hope I didn't violate the Expedition Portal terms of use...

Thanks.

 

[mongoose2231]

hahaha, i was thinking the same, lol

 

[Stoffregen Motorsports]

Great minds...

So we're actually thinking of going with 3.70 gears. I'm on the fence, but it turns out that mileage is big on the owner's list. I think it will be ok, even offroad. It will definitely make first gear usable around town, as it's a granny gear and totally useless right now.

The BJ74 that I built a while ago came to me with 3.70's and it wasn't a pig.

If anyone has run 3.70's in a FJ60, please chime in with your opinions.

Thanks.

 

[bdyer]

370s

I did an LS swap in my 62 and I run 32" tires. I had 4:11 but changed out to 3:70. It dropped my rpms about 250 at 75 but I haven't noticed any improvement in mpg's.

 

[jalbrecht55]

Not an FJ60-- but I have a Chevy Silverado half ton with a 4.8, nv3500 manual and 4.10's. (I think the standard gearing was 3.73, but I got the optional 4.10's). It came with 245/75R16's factory, but having ran stock and 265/75 and 285/75, I think the gearing works out pretty well, probably best with the 265/75R16. I found with all three tires, on the highway I wouldn't mind another gear, (I kinda want to upshift). Having said that, with the 285's there were times, especially towing where I could see running 4.56's, actually. Running empty, all three tire sizes worked fine. There are times on hills cruising at 65-70, I'll notice it's nearly floored with the cruise on, but generally it isn't working too hard. Speeding up to 75 or so, it actually seems to cruise up the hills easier in 5th! You can look up the ratios, but fifth is approx .73, which would be similar to his H55 OD with 3.70's in 5th.

I think your idea to run the 3.70's will be ok, but it does depend on how heavy this is and how much more drag there is compared to my Chevy. Mine is a stock height std cab/6.5' box, 4wd, 4750 lbs as it sits without me in it. The 5.3 does have a little more grunt, compared to my 4.8 which will help.

 

[huntsonora]

I'm in awe of your work....

 

[Stoffregen Motorsports]

Thanks everybody for the input.

Towing is definitely going to be a concern with 3.70's. I don't know where the RPM/shift point is with that engine, but he may have to drop down into 4th while towing up inclines. 5th is only .84 so dropping down a gear won't be the end of the world. I've owned three vehicles with 5.3's and for the most part, the power down low is good for cruising. The only time I hated it was when I was towing my Rover across HWY 50 to Moab and the gradual rise in elevation over the 110 miles from Fallon to Austin (NV) had the transmission hunting back and forth quite a bit. It definitely towed better above 70mph. Kind of an apples to oranges comparison though with the auto vs manual and the weight of the load I was hauling.

Thanks for the compliment, huntsonora.

 

[Stoffregen Motorsports]

Just finished the 3.70 R&P swap. First impressions? I like it.

For this truck and it's intended use, they should work out fine. Now let's see what the mileage gods bring...

Only one manufacturer sells the gears though. Randy's. And they weren't cheap.