Hey guys, I'm an LS-Idiot. I've been considering doing a 5.3 swap into my '56 F-100 daily driver (already has SBC /TH400 & 2nd Gen Camaro Clip). I don't know much about the LS engines, but I'm here to learn more. I intend to keep my TH400 because I have 2.94's out back and it drives fine. Later down the road I might swap in a T56 and some 3.73's but not anytime soon. I've only recently considered this engine swap, so I might be missing some things, maybe you all can help.

Here's my list/plan...
-'99-'03 5.3 Truck Engine with accessories, harness, pcm
-Flexplate Adapter Kit to use my TH400 behind the LS
-Current Performance modified stock wiring harness
-Current Performance programmed PCM
-Motor Mount Adapter Kit with rubber mounts
-MSD Inline Fuel Pump & 10 Micron Filter
-Lokar Throttle Cable
-Lokar 2-hole Cable Bracket
-Stock LS Exh. Manifolds with collector adapters
-Mechanical Gauge Adapter Fittings (Oil/Temp)

If I overlooked something, please bring it to my attention. Also, if you have experience using any of the parts I listed above, please post your opinions.


My questions:

1. Does anyone know the difference in the length of the 5.3 LS and a 350 SBC? I don't have much room between the valve covers and the firewall with my SBC...is the LS motor going to hit the firewall? I know there are offset adapters, and I can always beat the firewall into submission if need be.

2. How does the cruise control system work? Is it built into the PCM or something? If not, how can I make it work with my setup?

3. My truck has a 2nd Gen Camaro Z28 Front Suspension Clip. Will the 5.3 Truck oil pan work, or will I need a different pan/or to modify my pan?

4. How many o2 sensors will be required? Are they in the exhaust manifolds or will I need to put them in the exhaust pipe with bungs? If so, how far back from the collector flange of the manifold?

5. Does the fuel system require a return fuel line back to the tank? Can I just use one of those fuel filters with the 3rd nipple or does it need to go back to the tank?

6. How many wires from the stock harness go to the rest of the vehicle and what are they for?



Any help/info will be greatly appreciated. I intend to learn all I can from this site and take everyone's opinions into consideration. I plan to collect all the parts I need, have the harness/pcm done after I get the engine, and be ready for a quick installation over a long weekend. I just want to be well prepared for the conversion so that there are no major follies when the day comes to do the installation.

Thanks!

 

TVS cable for the TH400 to, unless your using a manual Valve Body

My questions: (Answers

1. The Gen III/IV engine is about 1" shorter.. the missing 1" is at the rear of the engine, it is the flange, if you compare the rear flange you will see it is very short. This is why you can not use the 2 O'Clock position to bolt up the transmission.

2. There is a thread on the forum of how to get cruise control. Not sure if it will work with your setup. Try a search.

3. The Truck pan will fit.. but hang very low below the crossmember.. I would suggest a F-Body or some after market pan.

4. Two (2) are needed, you can have post Cat ones deleted out of the tune..the closer the better... Depending on what mainfolds you hae, some have the O2 in the mainfold, others maybe down stream some of the mainfold. But if you can keep it about the same as the donner car/truck, that should be a good location.

5. Yes on a return line. .use a 99+ Vette FPR near the tank and then you will have a short return lilne.

6. There is a good sticky at the top of the section on what is need. But the main wires required to turn a harness into a standalone:
12+ Bat
12+ IGN
Fuel Relay
Fan(s) Relay
CEL
ODBII connector
Tach
VSS output for Speedo


good luck

 

bczee, thanks for the info. Wow!