Engine choice

[8man]

Ok, going with a S10 frame under the 48. I want to go with a V8, just cause.
I plan to convert the motor to a carb and distributor. I want to hear the carb sucking when I hit it, and the real reason is my wife likes the look better, and it's her truck. So I'm going to be buying parts with either motor.

My question is should I go with a 91 5.7 or a 97 5.7LS?

I understand there is a difference in how they mount to the frame, but this is the start of the build and I have to build motor mounts either way. I plan to use a 700R4 on either, realizing there will be a flex plate adaptor necessary for the LS and both will need the TV (I wish I knew what that stands for, I know it is the kickdown control, but why TV) cable so I will need the correct connector at the carb. Wiring will be necessary for either since there are no wires in or around the truck right now.

The question is the LS enough better to go that route or will I be wasting time looking for one?

[dsraven]

tv stands for throttle valve its gotta be set up right as well,not just connected.

http://static.summitracing.com/globa...structions.pdf

go LS, carbed if you want. at some point you may want the convenience of fuel injection so then you are all set up except for wiringand a few other items. you will need an oil pan kit with baffle, dipstick and tube, pan, oil pump pick up. they are all over ebay. I used a camaro pan. the stock camaro exhaust manifolds will also fit between the frame rails if you are trying to keep the cost down, whereas the truck ones are too wide. the truck engines are cheaper to buy so price it all out and see what works better, a camaro engine, complete, or a truck engine and then buy the add ons. cheaper to buy a wreck and take what you need, then sell the rest. that way you get all the stuff that works together. noit as big a deal for you if you don't plan on injection. if going with a crate engine make sure to ask what it will come with. p/s pumps, alt. belt set up etc.
I know you want to go with a carbed engine and a ditributor but the injected LS engines can be made to look cool too. they start easy, run smooth, emit less odor and get better mileage. up to you though. if a daily driver I would go LS personally. thats just me.

have you read this little blurb?
http://www.lsxmag.com/news/everythin...-your-ls-swap/
or this youtube?
https://www.youtube.com/watch?v=Ix-pxwo7arA

[Dan in Pasadena]

Sorry 8man but I don't know why anyone doing a modern V8 engine install ESPECIALLY an LS wouldn't install fuel injection?

Not only do you get greater horsepower & torque but also much improved drivability AND much better MPG....not to mention less emissions.

FYI, you can use sbc valve cover adapters (as I did), a throttle body that looks like a carburetor along w/an air cleaner, you can relocate the coils so they are not visible. Yeah, you can still see the fuel rails but if they're black they're not super noticeable. Picture is a 2011 LQ4 in my '55.2.

Your call, but I feel we'd be doing you a disservice to not at least suggest it.

[_Ogre]

to each his own but i agree with dan and don't understand why you'd carb it
if your going to go carb and dist; just stay with conventional sbc

[Indian113]

I wouldn't carb a LS unless I had to. The cost of Intake with Carb plus the Ign system seems pretty high. I only spent around $800 for my 5.3 and $150 for stand alone Harness.

[mr48chev]

Add me to the group who thinks it is a bonehead idea to want to put a carb on an LS engine. The only reason for doing that is running the engine in a racing class that requires a carb. You loose a bunch of drive-ability right off the bat including performance and gas mileage that are the reasons you install an LS in the first place. Why wast the money on the newer engine if all you want to do is hear air rush into a carb and don't give a rip about actual performance? Just put a 350 with a cam and intake with a big carb an save about 3000 bucks.

[1project2many]

I know the LS engine is the favorite child for many engine swap projects these days. We're in the process of planning cam and lifter replacements for three of our 6.0l gas engines and a fourth will have the pan pulled for what is hopefully O-ring replacement on the oil pump pickup tube. The engines have between 140k and 170k. Regular maintenance is performed on all the vehicles as they're subject to state and federal review and oversight. OTOH we're still running L31 "junk" 5.7 smallblocks with over 350k that have the original cam and lifters and haven't had an oil pump problem yet.

Personally I'd stick with the SBC.

[dsraven]

Dan, thats a sweet looking engine. at first glance it looks like an older style unless you notice the fuel injection. even then, unless you know what to look for, a quick glancer may not realize what he's looking at really. exhaust tube spacing would prolly be the giveaway if the looker knew the difference in the first place.

[my56chevytruck]

Go BBC, all the way, carb included. Youre wife's got it right, here the carb sucking, the engine roaring. This is a Gen VI 454 with a 2nd gen front suspension. NOW, having said this, you're adding an additional 200lbs approximately to the front end, but that can be a plus if you want the suspension to squat some.

[Dan in Pasadena]

Originally Posted by 1project2many

I know the LS engine is the favorite child for many engine swap projects these days. We're in the process of planning cam and lifter replacements for three of our 6.0l gas engines and a fourth will have the pan pulled for what is hopefully O-ring replacement on the oil pump pickup tube. The engines have between 140k and 170k. Regular maintenance is performed on all the vehicles as they're subject to state and federal review and oversight. OTOH we're still running L31 "junk" 5.7 smallblocks with over 350k that have the original cam and lifters and haven't had an oil pump problem yet.

Personally I'd stick with the SBC.

Sorry, but for longevity I would STRONGLY recommend the LS engines over either an sbc or a bbc. Anyone who has ever seen the inside of an LS has got to be concerned over the six main bolts, the ay the head gaskets are secured.

Mike - the guy that did my install has done many, many LS installs. Each one he does he opens to verify condition and puts new rod, main and cam bearings, all new gaskets and more if necessary. So far he says he's never had to bore one. they're all mic'd and meet factory specs. And that includes ones with 180,000 miles and another with 203,000 miles.

My engine had 81,000 miles and he said it still had the factory hone marks in the bores and it was from a fleet Isuzu N series delivery truck so it got fleet maintenance, nothing more.

Frankly, to me the argument that the sbc is superior to the LS is ludicrous. There must have been those that argued the flathead V8 was superior to the then-new 265/283 small block Chevy engines in the mid fifties because they understood them from long history.

[1project2many]

Dan, I would be less likely to reply if you didn't single out my statement. It's obvious that you're a fan of the engine you've chosen. Although you seem to take them personally, my comments about LS engines are not intended to reflect on your choice. You are however saying the SBC is a poor choice and you provide anecdotal and often second hand evidence for claims of short life, poor efficiency, and poor economy as if the engine is fundamentally unable to survive and is completely unable to be fuel efficient or clean. IIRC your truck had a running 283 for many years before you embarked on completely changing the vehicle's character, including a modern engine replacement. Fundamentally flawed as it was, that boat anchor of a smallblock did survive for generations and probably worked very hard for you and for prior owners before being removed to make way for progress. Luckily it is gone now, hopefully to be recycled into something more modern, reliable, and fuel efficient.

When I respond to the LS suggestions I am trying to provide evidence based answers to the hype and over-excitement I see today in magazines and on forums. The LS engine has many technical advances over the SBC and can make far more HP per CI which is very cool. Then again, the SBC of 2002 had many technical advances over the SBC of 1955 when > 1 hp/CI was only a dream. This is the nature of progress. But many technically advanced designs can suffer from unexpected problems and the issues should not be glossed over.

In our fleet of over 100 vehicles I can track trends and vehicle history back to 2003 when our smallblocks were anemic low compression TBI equipped slugs. Though they were underpowered, we were able to get 200k miles from them fairly regularly before replacement was required. The L31's that replaced them in '99 were a completely different animal. Increased compression, low tension rings, improved fuel management, more efficient cylinder heads, and roller camshafts, along with improved oil technology allowed the L31 equipped fleet vehicles to regularly achieve over 300k miles on the original engines. I currently have a '99 in the fleet with 385k on the original engine. Last summer I retired two with over 350k. Note that's the same range or higher than many junkyard LS family engines.

The LS family engines (LQ4/L96) entered our fleet with an '03 model in '07. Mileage is currently around 150k for most of those vehicles and we're starting to see internal problems that we have not had in the SBC family. Prior to these engines I have never in 36 years as a mechanic had a roller lifter pin come out and destroy the block. It's happened in two of our LS family engines. Prior to these engines I have dealt with maybe one or two GM factory roller cam failures. We have at least three LS family engines waiting to be torn down for new cams. Prior to these engines it was rare for an SBC to show low oil pressure without a direct cause such as overheating, or being run out of oil, or having very high mileage. But we have two LS family engines which need to have pans pulled to investigate unexpected low pressure. Currently we have 22 LS family engines and 32 percent will have received major work before 200k miles. By contrast last generation SBC major repairs tended to be in the 14-18% range prior to 200k.

Our maintenance records are monitored by state and federal agencies. We change the LS engine oil at less than factory recommended intervals (OE for LS equipped is to wait until the "Change Engine Oil" warning illuminates, up to 5,000 miles.) Our drivers pre-trip the buses daily. We don't pull trailers or overload the vehicles. We use them exactly as they are designed to be used, and exactly as the SBC's (and Ford 5.4's) that run right beside them are used. So when a group of similar design engines need mechanical work in less mileage than other engines it's worth noting.

I have been "building" vehicles most of my life. My first road licensed vehicle was a '55 Chevy pickup assembled from a pile of different vehicles. I have spent many, many hours wrenching for fun and for work. And as much as anyone can, I know that working on a weekend escape vehicle when you'd rather be driving it is not fun. No engine is perfect but if today's most popular swap engine is inadvertently equipped with unexpected internal problems then those problems are worth mentioning. The SBC was reliable for many years and IMO it's still a viable and cost effective alternative in plenty of cases where the builder is happy with < 400 hp.

To the OP, sorry for the rant. TBI SBC will run forever and require very little maintenance. You're limited to about 300 hp and will require custom tuning to really make it work.

[mr48chev]

Well it looks like we may have scared you a tad but if all you want is to hear being sucked in by a carb and that makes you happy the big block like My56Chevytruck suggested will do that in spades.

On the other hand there are no doubt after market air filter elements out there that will let the inlet of an FI engine make a lot of noise when you nail it. Most guys are going to do away with the stock LS filter setup anyhow. There may even be a thread on the net about what LS aftermarket air cleaner makes the most noise with positive or negative comments.