Vortec conversion question and answer thread (1 Viewer)

[Spook50]

This is mostly directed at @torfab and @orangefj45 but wanted to post it up for anyone else with the same questions as me. I have a ballpark idea of what to expect to spend on the conversion from Valley Hybrids / Cruiser Brothers and I'd be surprised if Torfab's cost is different by much, so I won't be discussing pricing or cost here.

As it turns out, I may be coming into some money in the next year or so, and if I do will be jumping on a Vortec conversion. It seems the favored engine is the 5.3, but I'll be going for the 5.7. For a while I had been thinking 6.0, but cost of aquisition, maintenance and overall availability led me to think the 5.7 is a much better option.

So my first question is about diff gearing after the conversion. Georg had told me a while back what transmission is typically used for the conversion, but I've since forgotten. Not knowing how the transmission is geared, I'm curious what the ideal diff gearing is for a 5.7 running 33" tires that would see about 70% pavement/highway and 30% trails (no rock crawling). Be great if the factory 4.11 gearing of a 62 could be used. Be one less step needed for me to worry about.

Transmission? Do GM transmissions usually run as hot as Toyota trannies, hotter, cooler? Regardless, I plan to keep my external cooler installed, so hopefully the GM trannies at least don't run any hotter than the A440F.

I'm told that the Toyota split case is retained and an adapter is used to mate it to the transmission. This would be awesome, and since it would be torn open in the process I'd opt for a full rebuild, McNamara gear and one of Georg's twins stick kits.

Suspension? Before I get into a conversion I'm planning to have done an OME 2/3" install, using heavy/heavy springs. The small block is not so tall of an engine that this wouldn't accommodate it is it?

Exhaust? Is a dual exhaust typically the solution? If it could fit under the truck, a dual 3" exhaust would be awesome.

How about gauges? If the OEM gauges are not retained, I imagine that would be a great opportunity to convert over to the Speedhut gauges.

I'm sure there are more questions I'll think of later and that others will think of and post, but this is all I got for now.

 

[SilverKast]

Torfab did mine earlier this year and I absolutely love my setup. It's an 88' FJ62 with the following:

- 5.3L vortec conversion
- H55F manual 5 speed tranny
- OME 3" lift (heavy/heavy) running 33's. Still running stock gearing, no problem with this lift and the small block
- Speedhut gauges
- single exhaust - not sure on the size but it's loud and reminds me of my Camaro SS. Lots of people remark on how great it sounds, although my wife thinks it's too loud (she's wrong of course, lol). Dual exhaust might look nice, but as far as sound what I've got is plenty as you can hear me coming a ways off and definitely tell it's not the stock 6 cyl

I love how it drives, it's nice and smooth on the highway, lots of power at pretty much all speeds, and it's a blast to drive all around. I probably average about 15mpg, although I'm sure I could do better if I really babied it.

It's a slippery slope though. Once you start doing one item you might as well do another while everything else is apart. And then another, and another, and another. Pretty soon it's almost a brand new old truck, haha. Totally worth it though and I have no regrets.

 

[cruisermatt]

If you're going to buy a used engine the 5.7 (LS1) is a pretty poor choice, mostly because everyone has a hard-on for it (like you do) for no good reason. Get the most complete, running truck motor for your money. The 6.0 is nice. The 5.3 is nice. The 4.8 is nice. The LS1/LS6 5.7's are nice too but certainly not worth the premiums people want for them just because they're a "Real LS motor".
Plus, the truck accessories will work better in a 60. They're all in the right spots already, no relocation BS needed.

Unless the 5.7 "vortec" you're referring to is the 350 SBC based TBI motor from the late 90's, in which case you really need to re-evaluate that idea.

 

[Meatdawg]

Here is my set up for you to reference...
1989 FJ62
6.0 & 4L80E using stock Toyota T-Case with adapter. No issues with the trans running hot.
35" tires & 4.88 R&P with Detroit Locker in the rear
4" OME w/shackle reversal
Single exhaust with stock manifolds. (not sure on size, but pretty sure it is 3")
All factory gauges are connected and work, except the tach. I plugged in a scan guage II which I reference for the RPM's and many other things.
This has been my setup for over 10 years now and I have had no issues. It is not a daily driver and sees maybe 3-5K miles a year,
I would guess for your application, the 4.11 R&P would be just fine.

 

[krice118]

I am curious why an older 5.7 would be more desireable than a 6.0 or the 6.2 for that matter?

 

[Spook50]

I am curious why an older 5.7 would be more desireable than a 6.0 or the 6.2 for that matter?

My line of thought was the LS1 5.7 has more power than the 5.3, but easier and more cost effective to source than a 6.0. If what @cruisermatt says is true though, maybe a moderately built 5.3 would be the better solution. Simple stuff just for some more oomph, nothing crazy. Headers, exhaust, larger throttle body, performance ECU and call it good. No need to dig into the whole rotating assembly or go with aftermarket heads or anything like that. I have no intention of racing my truck, though I do want it to get up and move when I get on the pedal.

 

[cruisermatt]

My line of thought was the LS1 5.7 has more power than the 5.3, but easier and more cost effective to source than a 6.0. If what @cruisermatt says is true though, maybe a moderately built 5.3 would be the better solution. Simple stuff just for some more oomph, nothing crazy. Headers, exhaust, larger throttle body, performance ECU and call it good. No need to dig into the whole rotating assembly or go with aftermarket heads or anything like that. I have no intention of racing my truck, though I do want it to get up and move when I get on the pedal.

My stock 5.3 (L33 which has about 20 more HP then a regular old LM7) will easily pull my 5500lb rig with 35” tires to 100mph within a typical highway merge distance.

And then continued pulling hard at 125mph which is where I let off.

Have you ever doubled the power in a vehicle before?

 

[Willard]

If you are moderately building it, then just get a 6.0. Pay the little extra and get the better engine. It is a LQ4 you are looking for. They are still cheap and great engines. I have one on a stand now waiting for new heads (PO punched though a water jacket, but the engine was free to me so minor cost) that will go into the 60.
Engine wise all I will do to this is replace the heads with OEM and stock ones and that is it. No need to build it up.
I plan to keep my H55f but upgrade to 4:11 gears with lockers. I think the 3:70s will be fine. The 2F is ok on the highway...just slow on the big hills.

I also have a 6.0 in my Yukon Denali AWD. It is a beast of a vehicle. With a curb weight of over 5700 lbs (1000 lbs more than the 60) that 6.0 pushed it with ease and is looking for more. 325 HP and 365 lbft of torque. It is no slouch. Plus minor upgrades ( like new heads if you want) will push 400 HP with ease. Add a cam and even higher. you are however placing this into a moving brick.
That truck has 3:70's with the standard GM 4 speed trans.

Now these are at 5000 rpm and 4000 rpm for numbers. But you get the picture.


Around here a 6.0 will run you anywhere from 800-1500 with computer. Pick up the whole vehicle for 2K.

I had a 5.3 in my Tahoe......not a fan, just me though.

 

[RredFJ40]

I don’t have an LS1 but I have LS1 heads and cam on my LM7. YMMV but I miss the low end torque of a truck motor. It’s great above 2500rpm but is really missing the oomph below that. I would imagine that, while a 5.7 may have some more HP it really makes it high in the rpm range due to the cam and runner profile. It’s a car motor, not a truck motor.

All stock gauges work, I used an Fj62 tach with a Dakota digital signal converter. Works like a charm and easily adjustable.

Edit: exhaust: dual 3” is huge, not much back pressure and will be loud. When I had my exhaust done I had ordered a MagnaFlow dual 2.5” to single 3”, my exhaust guy steered me to the same muffler in a 2.25/2.5 variety and I’m very happy. If I went with a larger motor the 2.5/3 would have been a better choice.

 

[Elbert]

5.3 or 6.0 GM truck engine is the way to go with matching GM transmission. My view, and certainly able to find these as the production of these engines has been ongoing for some time now. You want to mimic the stock exhaust from a GM pickup as close as possible. With 33 tires 4.11 is a good pick.

 

[Spook50]

I'm not really concerned with fuel economy (though it is a nice feeling when you find out you're getting more than you expected), and I'm sure a 5.3 would be plenty of power for my 62 (which once I have new front and rear bumpers will probably weigh close to what my brother in law's Silverado 1500 weighs. His has a 5.3 and it hauls ass), and with a couple tweaks would really fly, BUT, if I could get a 6.0 for a decent price and be able to easily maintain it for the many years I'd plan on having it, I'd go that route. Honestly I see pros and cons to each one versus the other, and it'll probably fall to which can be gotten quicker, in better shape, and/or less costly than the other once I take the plunge.

 

[Willard]

I could get a 6.0 for a decent price and be able to easily maintain it for the many years I'd plan on having it, I'd go that route. Honestly I see pros and cons to each one versus the other, and it'll probably fall to which can be gotten quicker, in better shape, and/or less costly than the other once I take the plunge.

What kind of maintenance are you talking? My 6.0 in the Yukon in 6 years of ownership, engine wise outside of regular maintenance, I replaced the Idler pulleys and the water pump (new belts at that time). That is it and that was at 150K. So far it has been solid.

On the 6.0 I will put in my 60, as it is on a stand now, I decided I will do the oil pump, timing chain. Put all new accessories on it (water pump, Alt, AC comp, PS pump, idler pulleys, etc.) This way I should not need to look at thee things for years.

But I would do that to any engine before I installed it.

 

[Shes Mad]

Here is my experience.

Gearing-4:11 is right with 33. Approx 1950 rpm at 60. 2200 at 70

Suspension- lift is fine. You need a different oil pan, and extend the bump stops in the front or you could hit the pan with the front diff.

80 series oil trans cooler fits behind the grill.

I used all stock gauges. Took sensors out of the 2f and put them in the ls. Needed a Dakota digital module for the speedo. With 33’s and 4:11 speedo is about 2-3mph fast. Mine is a 60, not a 62

I put a Z06 cam in a stock 2001 pickup 5.3. 374 HP at the crank on the Dyno . Stock LS3 manifolds.

You can loop exhaust over the transfer case, or cross in front. 3” would be tough, but fit whatever you can.

Make sure you have AC compressor and manifolds on b4 you lock in the engine mount position. They are clse on each side, but fit if positioned right.

 

[tmxmotorsports]

Should look like this when finished lq9 4l80e to Toyota split case 3.70 gears 32 inch tires

 

[MANUCHAO]

After driving a Gen-III 5.3 with an 4L60E AT for more than a few years...
I say go LQ9 or Gen IV 6.2...
With 6L80 or a 5 speed manual...

 

[AggiePE]

I have the LQ4/NV4500 setup and love it! Plenty of power! The LS engines (5.3 and 6.0) are cheap and can be found anywhere. The harness/ecm is simple to make it a 4 wire hookup and can be programmed cheap by lt1swap.com. Check out my build thread for more details. You cannot go wrong with the 5.3 or 6.0 engine. I kept the factory 3.70 gears and run 33x10.5x15 BFG A/T’s. I ran dual exhaust to the muffler 2.5” on each side and then a 3” outlet on the biggest muffler magnaflow makes. I kept all the OEM gauges (they all work) and run a scan gauge to monitor the actual coolant temps and other engine parameters real time.

 

[Spook50]

After looking around a bit online, I'm starting to like the idea of the LQ9 and a 6L80. I won't do the swap on my own though. It would be done either by Torfab or Valley Hybrids. I live much closer to Torfab, so the deciding factor once I'm ready to pull the trigger will be how much time I can take off to deliver my truck and how long I can go without it while the conversion is done. If I go with the LQ9/6L80 combo, I'll let whichever shop does the conversion figure out the best exhaust setup and other details. I'll definitely go with Speedhut gauges when I get it done though, including an additional tranny temp gauge, likely mouted on my A pillar where my current Autometer temp gauge is.