I have been on the verge of selling my 3rd gen for about three years and could not figure out after many opportunities why I could not let it go! I guess Im just attached...ha. So now I have decided to try an LS1 swap. Thankfully I have a good friend to help with the challenge.

To start with the plans are

what I have so far
LS1 short block
5.3 heads
6.0 truck intake (should still fit under the cowl hood I will use)
Truck coils
Water pump
wiring harness
injectors
starter
ac compressor
alternator

Trans plan is a T56

I was hoping to start a discussion with you more experienced guys on pros and cons of what I may be doing.
I would like to get into the 500 hp range NA. Or if you may have a few ideas on how to get a little more out of it. Trying to stay away from power adders for now.

Thanks guys

 

Welcome aboard thirdgen.org.

I'd pass on the truck intake. 500 HP may be possible, but an LS6 intake will make it more likely. A cowl hood is a liability, not an asset. Spend the money on a better intake.

Do you have a source for the T56? Not all are made equal. You'd be best off with an LS1 f-body version.

Were you thinking truck accessories (water pump, alternator, AC)? Again, you'd be better off with a Vette or f-body set-up.

 

Are you looking for 500hp at the flywheel or at the wheels? Do you have a budget number?

 

Are you sure though? I've heard conflicting things.

I've heard that if you want, you can take a complete LSx truck motor (4.8/5.3/6.0/6.2) and jam it into a 3rd gen and everything including all the accessories will fit and work AS LONG as you have a 2.5-3" cowl hood. Now, I dont know this for certain, but ive seen a few pictures of these engines swapped into our cars and they were still running the truck intake.

If he already has the intake and can get say a complete take-off from a truck engine, it would be cheaper to use all the truck accessories and what not then it is to use the F/Y body stuff, no?

Of course no matter what you have to change the oil-pan & pickup to an F-Body or swap style pan. But you get the idea.

 

I have one 5.3 truck intake and one 6.0 truck intake. Also a truck water pump and an F body water pump. I have an F body compressor and alternator.

I have heard conflicting things on the intakes. I have been told a lot of guys spend extra money on there intakes that there heads cant even handle. From what I can tell from a little research is that the truck intakes have clearance issues in an fbody, but the 6.0 truck intake will flow just as well. But I may be wrong.

If I was going to use ls 6 heads it would make more sense to me. But im going with the 5.3 heads for more compression. A few guys on the ls forums have done similar builds.

What are you guys finding as a reasonable price for the t56

the budget idea is to take my time do it right, but dont go crazy and bounce the bank off its foundation

 

Which 5.3 heads? The 799's have the same ports as 243's, with smaller chambers.

An LS6 intake will improve a stock headed LS1 (853 or 241 heads).

Powerwise, the truck intake sits between the LS1 and LS6 intakes, all other things being equal.

You need a mighty wide cowl hood to clear the truck alternator. A ram hood is the only one I've seen that was verified to clear (and he was using an L76 intake).

 

799's and 243's are the same, just cast in different locations. the only 243's that would be different are the ones that came from Z06 corvettes with the sodium filled valves. combustion chambers and valve size is the same otherwise.

op, stay away from the truck intake, and prepare to spend as much on your transmission as your engine! t56's come at a premium, and good low mileage units are expensive, but you get what you pay for.

 

As one whose done the swap, I can tell you its 100% worth the time and effort. Even my stock LS1 with headers, lightweight flywheel, and cold air intake is a blast to drive. Eventually I'm hoping to do a head/cam swap and I'd love to see ~420rwhp and mid 11's.

For big power N/A, you can use the stock shortblock, but nearly everyone uses a ported head, aggressive cam (~230@.050) and all the supporting bolt on mods.

Some advice:

-Research is free, and do lots of it. Join LS1tech.com IMMEDIATELY and start reading, searching, learning.

-Which wiring harness do you have? The truck injector connectors are different than the LS1/car setup.

-Use the F-body water pump. You'll still need an F-body PS pump, and alternator brackets. Your LS1 crank balancer/pulley will be compatible.

-Junk the truck intake. Seriously...hit the LS1tech classifieds and get an LS6 intake and you're good to go. The truck flows great in lower RPM, but due to the long runners it isn't good up high.

-5.3 heads? If they're the 799 casting number (as five7kid) mentioned, those are excellent.

-Notch the k-member. It'll fit without doing it, but just barely...I notched mine and it gave enough clearance to install the engine from the top. Well worth the effort.

Lastly, forget "cheap" or try to save money by inventing a shortcut using oddball parts that you may think nobody else has tried. I had a complete LS1/T56 takeout, and even though I got it for $3500 I still had nearly $6500 in the whole swap. I feel like I did it "right" though, which was my goal throughout the project.

 

 

If your time frame to do your swap is not critical be patient and search for a wrecked F body 98 to 02 and harvest everything you need. I bought a totalled 98 T/A and swapped the complete drive train wiring, fuel system, pcm etc and parted out what was left over. After a $500 trip to the exhaust shop for a new y pipe and converter I had all the right stuff that fit and works great. Hawks engine mount adapters are a must and trans mount can be fabbed or bought. All in all my swap cost me around $1200 total and now my 92 runs like a champ.

 

Kyle-

I'd love to check out your swap sometime. Im in O'Fallon.

 

We can do that soon, I'm in the process of interior reinstallation. I actually started this as a low buck toy for my wife since she won't drive my 67 and really got excited when I took it out for the first test run and couldn't keep it strait down the road. What an upgrade at a low cost. Pocket and 57 kid are a tremendous resource to ls newbies like me.