5.3L Swap?

[ZmOz]

I've recently found a used 5.3L engine and automatic tranny from a wrecked '01 suburban for about $1500. My '79 C20 currently has a 454/TH400 that has been around the block a few (hundred thousand) times.

As much as I love having a 454, the 5.3L is the same torque and 80 more HP stock than my 454, much more reliable, and probably gets at least twice as good of mileage. Would the 5.3L and tranny by chance be a bolt in for my truck? I've been pondering a fuel injection swap for the 454, but a whole drive train swap probably would hardly cost more.

Decisions decisions....

[N2TRUX]

No, it is no where near a bolt in. It may be worth the trouble, but it will take a decent amount of expense and effort to convert to any of the LS based motors. You will need the motor, transmission, computer and harness for starters. Then you will have to have the computer and harness modified along with different motor mounts and transmission mounts. And that's the short list.


If your looking for the easiest route you should consider a GM crate motor as a replacement for what you have...

[ZmOz]

Originally Posted by N2TRUX

If your looking for the easiest route you should consider a GM crate motor as a replacement for what you have...

That would be at least $1500 just for an engine without accessories...I can get the 5.3L, overdrive tranny, most of it's accessories, computer, and harness for $1500.

[Tom]

Originally Posted by ZmOz

That would be at least $1500 just for an engine without accessories...I can get the 5.3L, overdrive tranny, most of it's accessories, computer, and harness for $1500.

And spend another $1500 making it work
Its not worth the hassle IMO. It would be so much easier to put a FI vortec 350 in there or just the vortec FI from a big block on your current 454. Again were not saying it can't be done, but its difficult. I belive n2trux's has done this swap or was going to on his blazer.....

[N2TRUX]

Tom is correct. Even though the cost has come done quit a bit since I did the LS1 conversion in my Blazer your still going to spend 3-5 k by the time it's all done.

I'm not trying to discourage you, just warn you that the cheap price of the motor is just where your expenses begin.

[ZmOz]

What could possibly add up to $1500? So the motor mounts are a little different...that's not a big deal. I found this page in google, which says:

We showed you that while not a direct bolt-in for your old 350, these engines are easily adapted to any chassis that can fit a traditional Chevy V-8. In fact, the Gen III engine is shorter and lighter than the old small-block, but the bellhousing pattern has gone almost unchanged so these engines will work with most of the popular transmissions.

Even if it did cost $3000 total, I couldn't put in a 285+HP fuel injected small block with all serp. accessories and an overdrive trans for any less...and it wouldn't get as good of mileage as a 5.3L.

[Izzy]

Originally Posted by ZmOz

That would be at least $1500 just for an engine without accessories...I can get the 5.3L, overdrive tranny, most of it's accessories, computer, and harness for $1500.

Unless it's all the accessories I'd look elsewhere, those accessories can start adding up quick.

http://www.hotrodlane.cc/77chevytruck/77chevy.htm

[gn4u2c]

Do it !!!!!!!!!! Next engine in my 85 is going to be a duramax deisel !!! Think I'm crazy for spending $5,000 for the duramax,allision,t-case setup . maybe have to go another 1,000 in extras. Well when it's putting down 400 hp and 700 lbs of tq and getting close to 20 mpg for the next 250,000 miles I will be all smiles. Once you get old and lifes over you cannot go back and do the things you wanted to try so wing it !!!! maybe it will be great if not resell the motor and move on.

[boxrodz]

As the others have said, it is not a direct bolt-in but it is doable if you can handle the effort and the expense. Add to the short list: fuel pump(s), radiator and possibly the oil pan/crossmember issue. Sounds as though you have access to all the accessories, computer and wiring harness. You can get an aftermarket company like Speartech to modify your harness. Fiveeight's reference to Street & Performance's LS conversion is a good link. They have write-ups on other LS conversions that they have done on their site. Beware, their writeups make the conversion sound easy. There's a few of LS forums that have good information on LS conversions like LSTech. More folks are doing the LS conversion in many different types of vehicles. It takes a good bit of time to do the swap, but the results are impressive. Good luck in your decision.