Decided on a 5.3 swap, gathering my thoughts.

[jones20992]

Just a thought as this has not been covered in this thread,

From what I can guess this motor/ trans is from a 2wd truck correct?

If so you may want to search to see if the truck intake manifold will clear your hood.

With that in mind a truck intake manifold must go with truck accessorys, and a car intake manifold must go with car accessorys.

If you plan on using a cowl hood to clear the truck manifold be sure that the it will also clear the alternator and the purge valve.

I have never done an ls swap on a gbody so am not sure on these things.

Also how good is your th350? the 5.3 starts at about 275hp range and a cam/springs/ program can get you close to 400hp

If it was me I would ether make sure that the th350 has a good build and a MILD shift kit as I have learned that too firm of shifts at 6800 RPM can tend to destroy stuff real quick!

I dont feel the 4L60E to be a decent option because in my opinion the 4L60 can hardly handle the stock 4.8's in the trucks let alone a cammed 5.3, and the 4L60 just takes a lot more money to build right.

When I last did an ls swap (98 2WD s10) the stock 4L60e lasted 13 minutes the first th350 (stock) lasted about 2 weeks the 2ed th350 (mild build) lasted about a month, after that I went with a mild build 4L80e and it was still in the truck when I sold it

I hope this helps.
although just some more information on that when I went to the th350 I also went carbed, and when I went to the 4L80e I used a 94 6.5 diesel Computer to trun the 4L80e, I did not like the lack of tunability with that and ended up going back to EFI.

I hope this helps.

 

[bigmandengo]

I also think it would be a waste and a step back to sell the 4l60e for a th350. You already have the 4l60e and you don't need any adapters or kickdown linkages rigged up to make it work. Just a crossmember and a shortened driveshaft like previously mentioned.

Your best bet to get this thing put together on a budget is to go with a 5.3/4l60e. Use the truck intake and the entire accessory drive. The low mount A/C compressor will even fit, despite the bad info on the internet that it doesn't. Grab an efi fuel tank from a grand national or 4.3 monte and that covers the fuel system.

 

[grand86prix_05]

Well as far as the trans, I was worried about a couple things with the 4l60 such as does my shift linkage attach right up and wouldnt I need an electric speedometer? Granted, I dont need a speedometer right away, just sounds like id need a dash overhaul. I was also going to look more into the fuel system latet, but since it was mentioned might as well get a few details steaight. I saw somewhere someone saying to change to a wahlboro fuel pump and possibly the sender too. Would what youre saying be that if I simply take a fuel injected tank and hooked it up, itd pretty much cover my fuel system? I have been debating on replacing the tank and updating it in one go anyway, tanks arent too costly as is. Would work for me too as I am intending to clean up the frame and cover it up with some por-15 in this process.

Thats good news about the ac, I am thinking of removing my current compressor for now, but would love to update my ac system when i can afford it. I want this car to be fun to cruise in, look good, and lay some rubber when needed.

 

[bigmandengo]

If you use the 4.3 TBI fuel pump, you would need to upgrade the pump to a higher pressure pump. The grand national fuel pump should be up to the task of supporting a stock. Yes, the fuel injected tanks are a direct swap into all g-bodies except el caminos and wagons.

If you are going to use the stock 5.3 AC compressor, the commonly used adapter plate mounts probably will not clear the compressor. I used the spohn frame mounts and f-body motor mounts and that combination works well.

 

[grand86prix_05]

Glad to hear the fuel system will be as simple as I was expecting it to be lol AC will be a while, but using the a body mounts? Are they raised higher? Will they affect hood clearances?

I noticed I had missed a few questions. Yes this is a truck engine and trans, and I currently dont have a th350, was going to get one. I imagine the current trans will last me a while, but it seems as though either option will take a decent amount of work to work properly anyway and I have more/cheaper options with the 350 route. My only concern is the kickdown cable, but i still knoe it isnt a major issue to getting the car to run as is.

I have also read all truck accessories will clear the hood, only saw it depends on the alternator.

 

[onesickGSX]

I would stick with the 4l60e as well; it's the easier option at this point in the build. If you intend to do a top end upgrade at some point either a 4l80e or a built th400 would be the way to go. Just keep in mind you will need a different flex plate when using a th350, th400, powerglide, etc. as the ls crank is .400 inches shorter than a gen1 crank, and a kick down cable assembly will need to be fabricated. As far as gauges go, the only questionable gauge is the speedo, it would have to be an electric gauge if you use a 4l60e/4l80e. That or you would have to buy a different tail shaft housing that would support a mechanical cable. As far as an ECM I would definitely lean towards using a gm ECM as tuning options are worlds better. Hp tuners is 450 for their basic package which as far as I can tell the only benefit to the pro system is the ability to use a wide band o2 with the software. And if you where to do any other ls swaps in the future you just have to buy another vin credit from them which most where cheap 60-100 bucks. Sorry to hear your harness was cut but fixing it is still your cheapest and possibly best option as most prefab harness I've seen where in the 450-700 dollar range and most require using a specific ECM.

 

[grand86prix_05]

I understand that to a point it'd be easier, but I really like how the th350 is a direct hookup. I mean, I could also look into a 400, both would be fine to me. The thing is if I do decide to build up the transmission, it's going to be quite a price difference compared to trying to do it with a 4l60e. My buddy also believes, though I'm not entirely sure, but finding a truck 350 would be a pretty durable trans compared to the car versions. Sounds to me that it will last perfectly well against what I'm wanting to do, which is leave it pretty much stock til I can afford to do more with the car. Overall, if I sell the 4l60 for a decent price, the price now should be about the same and I won't have to worry about shortening a drive shaft or hooking up an electric speedo. Anyway, that's mostly why I'm looking at the 350 instead.

 

[onesickGSX]

So any updates; how's the swap coming along?

 

[pencero]

The truck 350 in my 79mc was fantastic. 100mph is only seconds away... youll never get the car over 110mph with it though,.

 

[grand86prix_05]

Thanks for asking onesickGSX, but unfortunately the only progress I've managed to make is unloading it out of the back of my truck. However, it may be rocketing forward shortly as yesterday my trans started acting up, guess the 3.8 is getting too rough for that 200c. I am kinda hoping that's just an easy fix though.

pencero, that is kind of a factor. I mean, I doubt I'd ever have a need to go faster, but I like the potential, and I assume the 4l60e would alot me more. I actually have been in a toss up as far as trans, I am kinda thinking I wouldn't mind a digital swap, but I can't make up my mind. Building an older trans would be cheaper, but if I leave it electronic a 4l80e is a possibility. This is putting me at a standstill.

I am planning on getting my mounts soon, after that probably start setting up the fuel system, then all the electrical. I still want to see if I can find someone to wire my harness for stand-alone, but haven't had time to source someone yet. I pretty much have all that figured up though, and am now trying to put together what I want to do for exhaust. I am thinking magnaflow cats with flowmaster super 50's, as I want it to be fairly quiet. Gonna be running stainless piping. I have also heard s10 swap headers fit, so going to be trying to source a cheap set of those, hopefully with a downpipe. The rest is pretty much just having it installed unless I can find a good catback system for this car from flowmaster.

Anyway, I think I have majority of this swap pieced together in my head, hoping I'm not missing anything. Thanks for everyones input, any further would still be awesome, I do appreciate it.