LS swap: pros and cons

[Ol' Curmudgeon]

I have a TBI SBC 5.7 in a car. It gets a consistent 21.5 MPG at 80 MPH. I haven't touched the system, beyond air filter changes, in the nine years I've owned the vehicle, and it is a 1992.

You could put together a TBI system using GM parts for a couple hundred bucks.

This guy does it on old IHC engines:

http://www.binderplanet.com/forums/member.php?u=1534

Folks are experiencing a 20% minimum increase in mileage.

Good luck!

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[Forty1Racing]

Nice thing about the LS is one can make big power if they have decent internals and an amazing port job.
www.wickedhp.com has started a series of turn key LS packages for off road.
The one we built in the pre runner has the same internals as a new style Camaro, that makes 1000hp w/ a vortech blower on pump gas. Our lil ls3 makes 600+ on pump gas and we only
Asked for 500!

Just as everyone has said, there is a 1000 different ways to make a nice SBC or LS. It's just a matter of what works for
You.
Best of luck with the project.


Sent using Tapatalk

[Forty1Racing]

I forgot to add by Decent internals
Those can stock ones in good condition from a junkyard or whatever.
My neighbor has an F body Camaro that is daily driven with 450+ hp (w/o the nitro ha) that has mostly OEM internals.
Pretty impressive!

[Zambo]

I have a TBI SBC 5.7 in a car. It gets a consistent 21.5 MPG at 80 MPH. I haven't touched the system, beyond air filter changes, in the nine years I've owned the vehicle, and it is a 1992.

You could put together a TBI system using GM parts for a couple hundred bucks.

This guy does it on old IHC engines:

http://www.binderplanet.com/forums/member.php?u=1534

Folks are experiencing a 20% minimum increase in mileage.

Good luck!

That is some cool stuff. I've got some reading to do.

[PDANK Racing]

I just fired up the 6.0l LQ4 that I swapped in for a 350. Haven't driven it yet, should have it out of the shop next weekend. She definitely sounds pretty mean with the stock cam, headers and a carb. The swap was pretty straight forward, t400 bolts up, TCI makes a conversion flexplate($250), your torque converter should work, Schoenfeld has reasonable prices on headers, the edelbrock/ msd setup ($700) for a carb'ed intake and ignition control is really easy to install and gives you the ability to set rev limiter and change timing curves(stupid part is they don't include the cable to attach module to your computer).
Shop around for your engine, a 5.3 w/ under 100K goes for $400 in all of the junkyards around here. I paid $600 for the 6.0 w/ alternator, and ps pump( which you don't need, the old style you have will work.)

Pros- stock lower end of Motor can handle whatever you put to it. Hot Rod mag did an article with stock bottom end of a used 4.8L and twin turbo'd the bastard to 1200 hp w/out blowing it up.
Good power as is
EFI- Good mileage
Some motor mounts will work with an adapter plate( we made solid mounts, super simple)
Great flowing stock heads
No distributor
Stock Coils are good until 600 hp range

Cons-
Parts are expensive
Gasket set is $450 to $650
Cam was around $300(w/out springs)
Pushrods are marginal
Oiling system is a little funky at high rpms(above 7000) for extended periods

[Zambo]

Thanks for all the good info fellas!

The 5.3 sounds like a really attractive option. Biggest worry I would have is packaging. Getting the motor with all the accessories should be no problem, I would just worry that I'd go to put it in my truck and some of the lower mounted accessories won't fit due to the cage and other fab work. Now its a whole new ball of wax. I'd need to find a shop that can set me up with the whole schmear and I'm not so sure how much that would run, but of course I could sell my 383 and carb to offset the price.

Affordable EFI sells the whole stock 90s chevy TBI system with harness, computer, RTR distributor and everything else for just over a grand. Problem is that the stock stuff won't support my cam, so I'd have to change that to a smaller one. The good thing about that system is that spare parts are cheap and easy to find, in fact cheap enough to just take a bunch of spare sensors and stuff with me. Could probably do this route easy for about 1200 bucks. I know I could just get their harness and ECU and piece the rest together but I'd rather just get the whole thing and piece together the spares just for peace of mind.


The Atomic MSD is a really cool looking unit and it can run my big cam. Also it has a user programmable and self learning ECU, which may or may not be a good thing for me. If I decide to up the power later on or do another project the Atomic unit should be good to 600-650hp. Probably looking at about 2500 bucks at least for the system and related necessary parts to go this route.


Decisions decisions

[BangShiftChad]

That Atomic unit looks pretty nice. Did you guys run a returnless fuel system or plumb a return line?

I've considered the 5.3 as well. Turnkey has a 400hp version but its like 7 or 8 grand I believe. I see 5.3 pullouts advertised complete for less than a grand but I don't know what it would take to get one up to the 400ish hp range. I like the 5.3 in my 03 Tahoe though, it pulls pretty good.

A simple cam and intake swap plus valvesprings and a 5.3 will make 400. Super easy.

[BangShiftChad]

For great EFI setups make sure to check out diyautotune.com as well.