68 sb, 283 vs 4.8 ls

[Heavymetl]

I've put over 6,000 miles on my 5.3/4L80E (and a turbo!) setup this summer.

Be warned, if you LS swap, your gonna drive the wheels off the thing. That's what always happens. Get a proper tune done on the engine too; the crisp throttle response, gains at all RPM, and smooth power delivery are great.

The old small blocks were great, but there's just better stuff available to the backyard hot rodder now. Have fun and good luck.

[Skinny Kid]

Quick Time makes a bellhousing to put a Muncie behind an LS. here's the link to it at Summit: http://m.summitracing.com/search?keyword=Rm6036

Definitely go LS, especially if you plan on road tripping it. The efficiency of the fuel injection combined with the cylinder head design just can't be beat. The 4.8 is a really under appreciated engine also so they can be had for pretty cheap. They have a near perfect rod/stroke ratio and share the block with the 5.3 so if you ever feel you need the extra displacement it's an easy fix. Good luck!

[Redline novdog]

Mine is to much of an original rust bucket to LS'it .If I had a mismatched truck then yes it would be a smart thing to do.Save your parts you take off!!! Somebody here might need them.

[sawman]

still think the older 283/327 carb/point engines are better less chance of breakdowns,simple to work on,i have one over 55 years old never been touched since new runs great,will a newer engine still run 55+ years from now? had a big car 67 caprice 283 car was ready to go at 90 mph,could cruise that big car at 110 miles on in without over heating,very snapy engine,build/change whatever you want but always the 293/327 is chevys best sbc ever made, {my option}

[jessemthompson]

Go LS, you will never look back. No throttle pumping or choke pulling. No cold start issues, great reliability, good power and good fuel mileage. It's the best thing I've done on my truck.

[hamjet]

Alot of us like old skool, and alot of us like the modern setups. the choice is ALL yours as it was with the rest of us. There's plus and minus with both, its a hobby we all enjoy and have something in common with. I'm old skool, (yea, I enjoy pumping the gas on those cold starts just to keep it running, but enjoy it, its what I grew up with). but I do enjoy seeing those new fangled engines in our trucks also. It makes it fun. You have alot of opinions now, Just go in the direction thats deep down in your gut and feel good about it....

[MARKDTN]

Originally Posted by sawman

still think the older 283/327 carb/point engines are better less chance of breakdowns,simple to work on,i have one over 55 years old never been touched since new runs great,will a newer engine still run 55+ years from now? had a big car 67 caprice 283 car was ready to go at 90 mph,could cruise that big car at 110 miles on in without over heating,very snapy engine,build/change whatever you want but always the 293/327 is chevys best sbc ever made, {my option}

I have to take a little exception to this and your other post in this thread. You do not see that many vehicles on the side of the road for issues that are truly related to fuel injection. My '01 Tahoe is approaching 300K miles. The oil is not black between 5K changes. I don't have to add oil between 5K changes. It has never had a valve cover off. I have never had to replace the starter or build the transmission. The original alternator went 200K and the water pump went 256K. It has never run hot, even when half the coolant was lost when the plastic radiator tank split. As much as I love the original small-block (and I have 2 running TPI 350s in vehicles) the new LS based stuff is so much better. You will not find an original 2-pc seal small block that doesn't leak at least some oil out of the valve covers and rear seal. With todays ethanol fuels, original carburetors have issues with floats and accelerator pumps. True, some earlier fuel injectors don't like ethanol, but you can easily get injectors that do. Original small block starters, alternators, and water pumps are more like 100K miles items-or less. TH400s are pretty bulletproof, but I have never seen a TH400-much less a TH350 go 300K miles. The few issues I have had, I was easily able to limp home and fix them. Parts availability is good too. The parts stores are carrying less and less of the old stuff these days. I have no problems with original small blocks, again I have 2 of them, but I do not think it is fair to say the new stuff is unreliable-it's very reliable.

[67 chevelle]

Originally Posted by MARKDTN

I have to take a little exception to this and your other post in this thread. You do not see that many vehicles on the side of the road for issues that are truly related to fuel injection. My '01 Tahoe is approaching 300K miles. The oil is not black between 5K changes. I don't have to add oil between 5K changes. It has never had a valve cover off. I have never had to replace the starter or build the transmission. The original alternator went 200K and the water pump went 256K. It has never run hot, even when half the coolant was lost when the plastic radiator tank split. As much as I love the original small-block (and I have 2 running TPI 350s in vehicles) the new LS based stuff is so much better. You will not find an original 2-pc seal small block that doesn't leak at least some oil out of the valve covers and rear seal. With todays ethanol fuels, original carburetors have issues with floats and accelerator pumps. True, some earlier fuel injectors don't like ethanol, but you can easily get injectors that do. Original small block starters, alternators, and water pumps are more like 100K miles items-or less. TH400s are pretty bulletproof, but I have never seen a TH400-much less a TH350 go 300K miles. The few issues I have had, I was easily able to limp home and fix them. Parts availability is good too. The parts stores are carrying less and less of the old stuff these days. I have no problems with original small blocks, again I have 2 of them, but I do not think it is fair to say the new stuff is unreliable-it's very reliable.

Very true I dont think anyone will deny the fact that the leaking issue has been fixed with the ls engines , and everything else you say I have found true allso ,for nostalgia or originality sbc are great , I have a fuel injected 383 stroker thats incredible , [it leaks oil] , but for reliability , mileage , power , light weight ,and reasonable cost , ls wins hands down . Put headers and a cam in a 350 , you'll gain maybe 50 horse , put headers and a cam in a 5.3 ls , you'll gain closer to 100 horse , they have better heads , and heads are where the engine makes power .

[fast&low]

I think the 2 sides have very good points but I also think if this was a voting thread the LS would win by a landslide.
And if the only way you could vote was if you had actually owned a sbc & an LSX swap LSX would win 100 to 0. IMO

[CastIron]

Personally, I'd probably go with the 283. It's simple, and not nearly as much work to install. And well tuned 283 should run fine for a long time. If you do go that route, make sure to find somebody that knows what they're doing when it comes to tuning. Carburetor tuning is becoming a lost art.
Newer, more modern engines can still have problems as well. I see lots of leaks on cars that are less than 10 years old. I also see quite a few newer cars that burn a lot of oil. I think it would surprise most people to find out how many "reliable cars" aren't nearly as reliable as the general public thinks.

[Heavymetl]

Originally Posted by 67 chevelle

they have better heads , and heads are where the engine makes power .

Plus:

Coil on plug ignition accurate to within a tenth of a degree
Gerotor oil pump mounted on crank snout
Low tension rings
Lightweight valvetrain
Stable cylinder block and bottom end
Optimum rod/stroke ratio
Hollow, lightweight camshaft
Greatly improved thermal efficiency (cool em with a heater core!)
Accurate fueling
Injector targeted directly at back of intake valve


And more I'm forgetting.

The biggest myth in hot rodding is "LS" engines make all the power in their heads.