I'm working with an 87 camaro with a 350 my dad built a few years ago and we put in this car with the factory t5 and a few add-ons like ls1 brakes, vette wheels, eibach springs, things like that. My problem is that soon this engine will go back to my dad for his 57 bel air and I have a VERY tight budget. I've found a great deal on a 99 truck 5.3 complete from oil pan to intake and accessories/brackets to harness, sensors, and ecu. Since it's so complete I believe this swap can be done cheaper than building the small block i've been saving up for and in the end still be more reliable, better mpg and all around better for everyday driving. I'm limited on time to pick up this engine so i've been up late the last couple nights researching and have lined up most parts I know i'll need:

f-body manifolds, oil pan, intake, and accessory brackets
ls swap engine mounts
ls swap throttle cable
and I know i'll need to fab a y-pipe
if there is anything else i forgot let me know

The last things i'm not sure about are the tuning and what to do about the transmission. I see there are programs and tuners that can 'tune out' things like rear o2's and the VATS system but how much do these programmers cost and are they simple enough for someone with no tuning experience to use? I'll be leaving the engine stock for now so is it 100% required to do this or will it affect how it runs if I just leave them unplugged? Also will it cause any issues using a manual trans with an ecu from an automatic truck, and what is the fix for that if it does?
My next issue is the transmission. I know from reading other posts the t5 is junk and I should throw it away because the first time I shift it there will be a fiery explosion and I will die. But...again I'm on a small budget and cant afford to buy a t56 right now. I do plan to add a t56 later when I have the funds so even though the t5 is holding up very well it is just temporary. I see there is almost 1/2" difference i need to make up at the crank flange and have found people adapting them with a taller pilot bearing with no problems. I see they use a big block bell housing and custom linkage or a universal internal slave cylinder because the biggest problem I think is the 11" clutch hits the t5 bell housing when it is bolted up. Is there a reason I could not have the 5.3 flywheel drilled and tapped to fit the t5 clutch and pressure plate I already have, and would that give enough clearance in the bell housing? Or does anybody out there make a big block bell housing that will clear the bigger ls clutch and can mount the t5 and external clutch master cylinder I have now?

P.S.- There are a lot of threads asking about adapting the t5 to a ls engine, but they are so cluttered with posts about how it shouldn't be done and how bad an idea is, that you can't find any real information so please everybody remember...I'm looking for answers not opinions. Thanks

 

By f-body manifolds, I assume you mean exhaust, and possibly intake. If so, that is correct.

Rather than buying a tuner or software, you might consider sending the PCM to someone who will tune out VATS, rear O2, and other unused emissions stuff, set your gear and tire diameter, and be done. Much less than the software, and most likely you won't need the software regularly.

One issue with the T5 is the VSS. Not sure what to tell you about that. And, I don't know the details of what would be required to get the T5 to work. Sorry.

 

Yes sorry I meant the f-body intake and exhaust manifolds. I also forgot to mention I plan to use the 4th gen tank and fuel pump. I think the ls1 used a returnless system is that correct? Does the VSS control some part of the engine programming? I converted all the gauges to autometer with the electronic speedo and have the converter on the t5 to work with that.

 

For the ECM look up spareecm on ebay, guys name is Rodney, he can tune the ECM pretty good for intial start up and driving (deleting anything you dont need). I used a 4th gen fuel tank, best bet is to find one complete with the pump, harness, fuel lines to rail and cut off the kick out lines, add a straight peice and use compression fittings to get it to the rail (just one line, the evap is unused off the tank, unless you plan on running the tanks evap system) Im not sure on VSS, I swapped pins on a my VSS TBI module since i had TBI in the car orginally and my speedo/tach worked fine.

 

The cheapest option for the bellhousing is the 621 bellhousing from the old big blocks. This will allow for the 11" clutch and you can then run the LS7 clutch setup (it is a little stronger than the LS1). Kesler makes a bellhousing that will work, but it is $270 or so. The positive of the Kesler piece is that it will allow you to use all bellhousing bolts. With the 621 you will have to leave one off.

The main problem you will run into with this is the natural canter of the T5 is 17* in our cars. Once you use the 621 bellhousing it will then mount the transmission straight up and you will need to figure out how to correct for that. The shifter could be pretty easy, just bend up a new lever, if you have the correct tools. The torque arm and transmission crossmember will be a little more difficult. You will need to make a new crossmember with a torque arm mount integrated in.

For gap, just use the LS7 pilot bearing to help make up for the .4 difference.

I have been doing research on this for quite some time to make sure I have everything planned out. With a stay at home wife and two kids funds are non-existent, so I have to plan down to the last dime. There are other pieces, but I am forgetting them at this exact moment. Good luck.

 

I forgot all about the angle getting lost from the t5 to the 621 bellhousing. So I've added up everything I know I'd need priced from ebay still comes up to at least $500 before even adding the clutch kit. I've seen lt1 t56 sell a couple times before for just a couple hundred more on ebay and craigslist, would the lt1 bellhousing clear the clutch and just use the ls7 pilot to make up for the shorter input shaft? There isn't any rush on this project so I would have time to watch out for a good deal.

 

The lt1 t56 uses a pull-style clutch, I am not sure that there is a flywheel that will bolt to a ls engine and use the lt1 style pull clutch. The lt1 t56 can be converted to a push style ls clutch, but typically is t cost effective...... Just something to look I to before to try to use a lt trans behind the 5.3

 

25th327RS is right. The LT T56 will not work with a LS motor. You will need to convert it and it is not cost effective to do that, unless you get smoking deals on the parts.

 

Well the engine is on the way and I also ordered a f-body fuel tank with the pump and all the wiring and should have it all in the next week or so. I'm still not sure what i'll do about the trans yet might even have to go with an auto for now but it will take a while test fitting and working on wiring so i'll keep a look out for a deal. I've also been looking at the f-body oil pans and for $300 new and still have to notch or hammer the k-member I'm thinking of going with the holley ls swap oil pan. The pictures I've seen seem to have good clearance to the k-member and ground and have room between the crossmember and pan to run the exhaust like factory for just $100 more.

 

Sounds like a good plan. I for one did not trim my factory crossmember and I will say it is tight! Not a big deal till you have to R&R the trans. The oil pan is practicaly laying on the crossmember so the engine wont lean back. Makes it tough to get to bell housing bolts. The more clearance the better.

 

Ok it's been a long time but I have an update with some good info and a new question. Got a great deal on a lakewood bellhousing for the t-5 3rd gens with a centerforce 11" 26 spline clutch and bought a nfw 1050 flywheel. Clutch bolts to the flywheel no problem and the bellhousing clears the clutch and flywheel easily. The bellhousing and clutch i bought came with matching flywheel for a sbc and there feels like no weight difference between that and the new ls flywheel, even looks identical except the spacing of the flange where it bolts to the crank. My problem is the bellhousing hits the 4 bolts at the top of the rear seal housing before it can get flush with the block. I see several different designs on these online. Mine is completely flat on the front and has a casting #12559287. I see some that look like the bolt holes are recessed a little. What are the differences in the different designs and will any of them fix this problem without grinding bolt heads or drilling for flush mount bolts?

 

Searching online just now I found that the rear cover and valley pan use the same bolts. I found a set of low profile allen head bolts in a kit that I'm going to try.