View Full Version : Lt 1 engine swap

fj40 ripper
03-18-2013, 07:19 AM
own a 74 fj40 with sbc 283 and auto turbo 350...old and tired...wanting fuel injected 350...looking at doing Lt1 swap...with 7004r trans...checked painless for harness and advance for adapter...can totally make this happen..wondering though if anyone has done this and was it worth all the time and money....thinking of tbi 350 or just staying with carb set up..not building race truck but for the price i can get the lt1 and 700r4 it seems worth it...any thoughts or suggestions...bought my fj40 2 mths ago and I love her..I also own 69 ford bronco...not an fj40 but sweet also...proud of both...and happy to of found and become member of club...my bronco club is great and this one looks awesome...hello all Toy owners..proud to be here...can't wait to get on the trails....THX...

03-18-2013, 07:40 AM
Personally I'd say the fuel injection and 4th gear are both worth the swap. But I guess it all depends how much you drive her and were.

03-18-2013, 08:22 AM
Welcome. Old and tired engine are better when they get refreshed or replaced. Sounds like you want to go the LT1/7004r route - go for it.:D

Post pics of your Bronco.

Uncle Ben
03-18-2013, 08:40 AM
Fuel injected over carb any day! LT1's are car engines and thus the torque peaks are higher RPM than that of the truck engines. You are already used to that with the 283 so 300hp over 200hp will be hugely noticeable! :D 700r4's are great tranny's as they have a 3.04 first gear plus a tall over drive. They bolt up to the same t-case adapter the t350 does. If the tranny is from a 2wd car or truck you will have to install the 4wd tail shaft which isnt that hard to do but does require unstacking the tranny to put it in. Another factor you might not know about an LT1 is it was the first GM engine to run reverse direction, which means that of course the crank spins normally but the water pump is spun backwards which requires a unique pump and correct cooling fan. The wire harness and ecu are fairly basic as the LT1 is an early OBD setup. Long time Toyota head Jon Davis has a tweaked LT1 in his FJ-62. I think he is running a 700r4 as well. I can get you contact info if you need it. That 62 is a running beast! :thumb::thumb: Good luck on the project and welcome! Old Broncos are AWESOME!

fj40 ripper
03-18-2013, 09:03 AM
Thx..for imput and warm welcome...Corbet is that your husky...I have four huskys..2 male and 2 female..Uncle Ben...would like his contact info..thx

Uncle Ben
03-18-2013, 09:20 AM
What year/generation LT1 is it? I assumed it was a second gen...

03-18-2013, 09:50 AM
Thx..for imput and warm welcome...Corbet is that your husky...I have four huskys..2 male and 2 female..Uncle Ben...would like his contact info..thx

Alaskan Malamute "Porter" He was a pup when that picture was taken.

03-18-2013, 10:14 AM
I've got a 350/700r4/np208 that I may part with if your interested. Engine has 2k on it since rebuild but will need to be converted over to TBI, it's currently a quadra jet. Let me know if you're interested.

fj40 ripper
03-19-2013, 06:55 AM
So I have heard that chevy high pressure fuel injection has a problem with vapor lock on the trail...good for road applications but not so much real 4x4in...heard tbi is where I want to go....low pressure fuel set up...easy of sensor and wiring connection...on Lt1 heard that optispark has serious moisture problems..not good for snow runs or any stream crossings....still trying to learn as much as I can before I pull trigger on new set up...the msd atomic efi is my ultimate set up but to rich for my blood...tbi seams the practical way to go...and with headers and some small mods should get about 250hp....

fj40 ripper
03-19-2013, 07:03 AM
And yes baja1d..intrested in 350 and 700r4...price dictates more intrest...what year motor and trans...how much hp in 350...friend said to stroke to 383 would give much torque...don't want to lose reliability or over heat...any imput on stroking...worth it..my dad says stock set ups 4x4's the best...thx

03-19-2013, 08:49 AM
I had a 383 in my FJ40. Never had any drivability or heat issues with it. Well until it caught fire :mad: That was probably the result of a loose fuel line but I'll never really know for sure.

Torque was awesome. That engine was 400hp/425ftlbs.

03-19-2013, 08:56 AM
I would avoid the LT1 and either go with a TBI 350 or make the jump to the LS based vortec motor.

Since you already have a SBC sitting in there, the TBI would be the easiest option (pretty much drop in and wire up). It's true that they need far less fuel pressure to operate, but that's also the rate limiting factor in generating HP. Stock, the TBI 350 is 210hp and 300 ft/lbs of torque. It doesn't sound all that great but it gets the job done and is bomb proof reliable and easy to cool. If it's not enough power, get a set of 94 and later vortec iron heads and bolt them on. That usually nets about 40 hp over stock. I would not jack with the cam. The TBIs are speed density EFI and don't take kindly to hot rod cams unless you are REALLY good with tuning. At that point, the projection is the way to go.

03-20-2013, 05:48 PM
I agree with Rockrod with the LS engine. I would go with a LQ4 5.3 vortec out of a wrecked chevy truck or tahoe. Those are bullet proof engines and can be found reasonably cheap. Be sure to pick one up with the computer and wiring harness. I'm looking for one myself to drop into a camaro. My plan is 350hp/5-speed/3.73 gears/25mpg/light right foot.

03-20-2013, 06:03 PM
Telly, a friend of ours put one in a RX-7 along with a tranny that had a long 6th gear (forget which) and kept R's low and was getting close to 30mpg.

My Brother has a 240 with an LS1 in it with lots of work on it and still gets good mileage.

I put a 5.3 in my 60.. It's standard block truck motor out of an avalanche and it does wonderfully. Vapor lock or cavitation before the pump is not an issue as long as you build the fuel system right. lots of misinformation out there as far as what an acceptable fuel system is i think. An inline pump with a filter before it just won't cut it when the fuel is hot... hi performance pumps that move a ton of fuel make it worse.

03-20-2013, 09:42 PM
I live and die by Denso fuel pumps. by far the best quality pump I have ever owned. I simply replaced the stock denso pump with a supra turbo denso pump and I have 65 psi at the fuel rail under all throttle positions and engine rpm. it flat works (and is whisper quiet).

03-21-2013, 11:39 AM
TPI all the way. Great motors... Built for cars but still great motors.