I'm not sure if impala injectors are the same 24lb/hr rate as f-body/y-body, but if so, they can support close to 400whp. If you want to keep it bolt-on and smog is not an issue then I'd try and get some long tube headers/3" dual exhaust on that thing. Forgot is since this is OBDII you will get codes if any of the smog **** is unplugged which will force the engine into open loop/won't run as efficient. You will also have to bypass VATS if you are not using the stock key ignition.

 

There's a VATS bypass module on Amazon, I've used them for years to delete that crap.

 

stock Impala injectors are 24#. If OP is doing a cam, he will need the pcm tuned for it. The tuner can delete any other emission items if OP location does not require emission testing. VATS can also be disabledThis assumes OP is using the donor car harness and pcm

this is another option for wiring harness.
92 - 95 LT1/LT4 Standalone Wiring Harness (psiconversion.com)

You will need to buy a pcm either used from a 96 or get a reman for a 96. I just bought the reman one for my 96 and had it tuned for my mods. pcm was $190. Rockauto has them and O'riellys also

 

I would spend the cash on that standalone harness, delete VATS, and simply send the PCM out for a mail order recalibration. It will just be a matter of unchecking boxes for the deleted emissions equipment. Tell them not to do anything else unless you want the enable/disable points for the fans lowered or something else that's simple. Leave all of the fuel and spark surfaces alone. I bet you could have the truck up and running in a weekend or two.

 

mail order tuners have a form you fill out for what you have (mods like cam, tire size, trans, etc) and things to disable if desired

I have used pcmperformance.com

Shortly, there will be software allowing OBD2 tuning yourself. Its in Beta form now.

 

Thanks for all of the info this definitely helped me out a lot. I will post more of the build soon. Thanks

 

Here's another monkey wrench to throw into the mix- Finding a tuner or tuning software for OBDII is going the way of the dodo bird. Supposedly there are a couple of mail order tuners out there if that's the way you want to go. However, if you are wanting to keep fuel injection/PCM you can easily change out the PCM to OBDI. From what I recall tuning software is readily available if you are interested in tuning on your own. Also, I do believe OBDI ignores such things as EGR and AIR. That's if you want to tackle tuning on your own.

 

eehack and scan9495 are free OBD1 software. You just need to buy the "cable". PSI makes a more streamlined harness so that combo is an alternative to OBD2

However OBD2 software that works with modern laptops (Windows 11) is just becoming available.

Moe Baily (Texas) and also Alex at pcmperformance (N.Y.) do mail order OBD2 tuning

 

Cams are very subjective I have built and had more than a handful of LT1 F bodys and transplanted way more. If you want to follow the kiss principle. My favorite was the LT4 hotcam it sounded good ran great and was stone *** reliable on the valvetrain with minimal mods. You could drive **** out of em and the valvetrain stayed together for many thousands of miles. It may not even be available anymore and sure there are better cams these day's but it was gm validated had a good split on traits and was stone reliable.

Get a standalone harness it's best place to start.

Old blackbox PCM's are hardly supported by anyone these day's OBD1 or II. However good old LS to the rescue for an easy tunable solution. I have done the below on several LT1 cars and swaps of mine and you can ditch the electronics section of the optispark so all it is a distributor only. BUT it will only work on 96,97 engine with a crank sensor. it will not work on 93-95 without updating to the 96 up timing cover opti drive opti unit reluctor crank sensor, balancer and balancer hub. Experimented with this about 10 years ago and found a reliable works like a champ method.
Run a 0411 LS pcm programmed to a 2002 chevy express van 5.7 vortec. This gives you the option of running a 4L60 or 4L80 E too because 1500 vans had 60E and 3/4 vans up had the 80E.
Pin in the donor harness to match the 02 van pinout. Turnoff codes for the cam sensor it's not needed. On a base 5.7 tune file it will start run and idle just fine so it can be tuned the rest of the way to suit your needs or tastes. It uses the crank sensor for crank angle trigger and does not have extended crank times.
All the LT1 Existing data sensors are cross compatible no changes required and the vortec trucks and Lt1's use same ignition module no changes required. It also allows you to run pcm controlled fans and hvac and add 3 wire refrigerant pressure sensor to even allow the fans to be ac pressure reference controlled You literally update brain only and leave everything else as is and the 411 can control it all correctly. Opti now functions as a distributor only.
The LT1 was the blueprint engineers used to design the rock solid vortec 350s that came in all 96 up trucks.

I'm in process of doing this swap right now on my 86 sierra. I had it in highschool and the hottest swap on the road was a LT1 and you were the fo schizzle if you had one. So when building this truck 28 years later it's getting the LT1 powertrain I wanted in high school but could only dream of having at the time regardless of how dated it may be nowday's.

 

You can still get the LT4 hot cam from a quick google search. It's probably a good option for a DD. Mine is pretty similar, 218/230, 114 LSA .495/.510 and I like it a lot. The hot cam is 218/228, 112 LSA, .492 / .492. Both cams listed with 1.5 ratio rocker arms, I run 1.7s to give some more lift. You don't have to change your timing cover with the Torqhead 24x setup btw, he just includes a spacer for 92-95 LT1s and he does offer a LS1 PCM setup. I just decided to go with a Holley Dominator ECU and EFIconnection harness along with the Torqhead crank/cam sensor though that is a good bit more expensive.

Going to be transplanting an LT1 into a 93 Thunderbird that **** the bed losing the timing chain and ate most or all of the pistons and valves.

 

Stock 350 displacement, stock compression with an automatic, tight converter, and highway gear I would probably go with the LPE-74211. The Erson cam Lloyd and I cam up with that I ended up with for the 383 in my heavy Express van is almost identical to the LPE-74219. It has a loose converter and 3.73 gears though. I have seen an 11:1 383 with the 74211 make 450+ HP and TQ with stock exhaust manifolds and cats on it, passed CA smog too. At 1.17 hp/CID that would put an equally setup 350 around 410 hp and 410 tq. 74219 would add about 20 hp but trade off some low-speed torque under ~2,000 rpm.

If you have a converter that stalls 2,400-2,800 rpm and atleast a 3.73 rear gear on stock height tires, I would not overlook the TPIS 'Lil Chubs' or the virtually identical Melling 22280 cams either. 220/224 @ 0.050 on a 110 LSA and right at 0.500" lift. That size of cam runs hard with some head work. I built a L30 305 Vortec with one that went into a 1980 Corvette. Little 305 with 059 vortecs that had a little work done on them, a Q-Jet, dual plane intake and long tube headers with a 2.5" to single 3" Y-pipe (thanks to GMs redesign making an actual dual exhaust more of a pain than it was worth on that car) put the Vette in the mid 12s on stock sized street rubber with the 3.07 rear gear and a 200-4R. Also managed over 27 mpg highway when I drove that car on my 120 mile round trip daily commute at times with the slippery aerodynamic body, that 305, the 200-4Rs 0.67 overdrive and the 3.07 gear.

 

I didn't even mention the LE cams his stuff was schiznit as well. Best thing to do is stay on the small side if you are goin to cam it. Or man in roadkill fashion flat get the old girl running first and foremost and then come back and mod it. Doin all the hot rod mods cams converters yada yada are what kill so many projects cause you run outta money so dang quick when all the mod money coulda been used to flat get it on the road. In stock form a LT1 is damm good running engine sure it's not LS.
But it sure as hell sounds better than an LS with a nice set of pipes.

I have one other suggestion to keep the cost down. If your's is a longbed you can run the big tank on the drivers side only use a sending unit for an 87 R10 truck and put a 96 vortec 350 truck fuel pump in it. simple quick and gm reliable. In 87 gm changed the models to R and V dropped the C due to it being a 6 month run truck. they applied the C and K to the new for 88 now OBS trucks.

 

A set of vortec heads on those old small blocks made just a day and night difference. Sounds like that was a good running little combo.

 

Hrm. LPE states the 7419 was more for long intake runners ala L98 and the superram they used to sell, and the 74211 was better suited for LTx/short runner intakes or mini-ram. Regardless a friend of mine had an MTI built 383 with the 306 cam which made 410whp and 390 torque. Ran a best of 12.0 @ 120 on stock susp and “H” rated tires. Installed a 211 and those dyno numbers were reversed. Same dyno, but sadly never took it to the track after the cam swap.

 

I ended up with the cam that was 74219 like by coincidence. Engine had a 271/284 @ 0.006, 218/228@ 0.050, 108 LSA and 106 ICL giving 0.578" lift with 1.7 rockers. Ended up dropping 1.5 and later even 1.3 rockers on the exhaust for a test. With the smaller rocker ratio it had improved drivability and more torque with each rocker ratio step down, the Thorley Tri-ys effectively were over-scavenging the cylinders. New cam ended up as a 268/268 @ 0.006, 219/219 @ 0.050, 112 LSA and 108 ICL and 0.542 lift with a 1.6. IVC close is slightly later, EVO slightly later, biggest change was reducing from 61.5* overlap to 44*. The first cam hated being under any kind of load under about 1,750 rpm. Comp absolutely blew it when they recomeended those cam specs for the setup, should have trusted my gut that they were full of it. Simply calculating the overlap would have told me what I needed to know. Sounds cool but not at all what I wanted.

The first cam made 412 whp and 430 wtq on 70% ethanol content pump E85 through a 4L85E and a GM 10.5" full float 14 bolt. Cannot fault it for making good midrange torque and making power to ~6,000 rpm but driveability and fuel mileage sucked. That is the old Comp cam. Actually have the intake off it now for the cam and an intake swap. It was running on 7 prior to that video because unknown to me at the time it had a massive vacuum leak in the crankcase from a leaking intake gasket that oil fouled a plug. First steps to change spark plugs, jack it up, put it on my 12 ton stands, take the front wheels off and remove the rubber like inner fender liners. Can get at 5 of the plugs through wheel wells, cylinders 5, 7, and 8 are easiest from underneath, lol. I actually came close to building a 396 LT1 for this before going with the 383. Had a lower mileage Cadillac Fleetwood engine with the hybrid mechanical/electrical fan setup I would have used.