dcaggiani

I am a big fan of the LS3 engine. They are compact, lightweight, reliable/dependable, and full of power. Out of the box you can get a 430HP crate for about $6000. If you want 500HP+, the LS3 out of the box can do that too - just for more money.

Of course, you will have to add the computer and wire harness not to mention a pulley system which all adds to the build.

You will never look at a small block again after crossing over to the new LS platform.

SledgeHammer 2.0

I thought I always wanted an LS powered machine till I built one. One thing I learned is that no matter what kind of warranty GM tells you they give you on crate engines and peripherals, the warranty isn't worth crap if you can't find a dealer to work on your car because it's too old and they don't work on modified cars.
My plug and play didn't plug and play, I couldn't find a dealer in Houston that would take it in and when I convinced a dealer to do so, it sat for 23 days without them even trying to fix it. I finally took it to one of those LS tuner guys who found a voltage drop issue inside the supplied fuse box.
I bought it all from Summit, who told me the warranty is covered by GM Performance, GM Perf. tells you any dealer will work on it, but you can't find a dealer who will, and GM Perf. won't help you in locating a Co-operative dealer. It's all just a big circle jerk from there, with them pointing the finger at each other.

Crunch527

I never would have thought to ask how all the warranty-side of the discussion worked or doesn't work...thanks for the insight...

GTOguy

I drive LS powered cars and the old school stuff. LS engines are what the SBC was in the '50's when it first came out: light, cheap, powerful, and durable. That said, I prefer an old school SBC in an old school car. I compare it to putting a Honda engine in an old Indian frame: the Honda has 5 times the power, is smoother, more reliable, etc, but there is something about the old Indian motor that makes it an Indian. Older cars are less refined and simple to work on, without computers and complications. A lot of guys like LS conversions. I'm not a fan. But then, I can't stand Boyd Coddington/Chip Foose stuff, either. The 383 in my '61 is old and tired, and built off of a road draft '67 block. It has 461 '65 big valve heads and the stock dual quad intake and carbs. It is scary fast at WOT, and gets bent out of shape easily if 'driven like a douche bag'. Probably still pumping out 350 honest HP. I can break the rear tires loose at 60 mph when I gas it in third gear. (narrow bias plies) All the excitement this old 'L7' needs!

Bill Pilon

How do you get 327 CI out of a 4.00" bore and a 4.127" stroke, it looks more in the 415 CI range to me.

Bill

Nowhere Man

GM does. They have put it in millions of pick ups, vans and suv's. It's called the 5.3

SledgeHammer 2.0

Yep....
Bore = 4
Stroke = 4.127
Cylinders = 8
Cubic Inches = 414.891292203682
Litres = 6.7989330613651

ejboyd5

How old are you (so as determine how many more new engines to anticipate in your lifetime)? How do you plan to use the car (daily driver, weekends, street racer, talking item at shows)? If it were mine, I'd rebuild the original 327 and be done with it as there are lots of other things to spend extra money on that will give you a greater return on enjoyment than added power in that chassis.

69ttop502

I don't know, that old chassis did ok with an L88 bolted in! Just sayin'

Nowhere Man

Bias tires kept them honest.

BK N 66

i guess you guys are right dont need that much HP As i wouild probably
start to break things? i dont race my car but do like to take it out on
the freeway and open her up a little bit. would probably maybe run her
at the drags once or twice a year?

i guess i should have stated in my post that my present motor is a
1970 4 bolt main 350 small block bored 30 over and i am running a
roller rocker comp cam with AFR aluminum heads and a msd ignition
750 Holley double pumper w/ mechanical secondaries.

had it dyno tested a few years ago and it made almost 350 HP to the
rear wheels. it dyno at betweeen 425-450 total HP.

i guess i should be happy with my present motor as it runs really
good and pulls really hard all the way to 7500 rpm.

i guess i just am tires of the oil leaks i have had over the last few
years. i keep chasing the oil leaks and cannot seem to find them and
get those damn leaks fixed?

after reading another post on this forum on a 383 stroker motor maybe
my oil leak is coming from the front timing chain cover??

i have replaced the oil pan gasket 3 times and it still oil leaks right
under the middle of to the right of the oil drain plug.

the leak is not coming from my valve covers or my oil pressure
line or my fuel pump. i notice the bottom of my starter has oil on it?

could it be my timing chain cover? this is my last hope. i will try to
take the timing cover off and put a new seal or gasket on it.

hope this does the trick. as i am getting to old and tires of chasing this
damn oil leak i have had for the last several years. too frustrating.

thats why i was think of putting in a new small block chevy LSX motor?

but for the 11k they want i think i can fix a lot of oil leaks on my
old motor?? it still runs like a brand new motor and is very dependable. i should be happy and i am if i can only fix this damn
oil leak. i would be happy to pay someone to fix this oil leak if they
could guarantee me to fix the leak?? i guess i am just too tired of
chasing this frustrating oil leak> thanks guys sorry for the rambling.

jrs 427

The LS 5.3 is quite the engine. A friend put one together. Dyno showed 400+ hp and not expensive to build. I would look for the aluminum version to keep less weight over the front wheels. Great all around performance, dependable, and easy on fuel.

GTOguy

Sounds like you're happy with the way it runs but unhappy with the mess. Do what I did to my '67 GTO 5 years ago: yank the engine, reseal the whole thing while it's out, repaint and detail it, and clean and touch up your empty engine bay. Put it back in and enjoy. I went from 20 years of leaving an oil trail to no leaks whatsoever. Just drove it 180 miles to a friend's house, parked it in his new driveway, and when I left 6 hours later, not a spot. Mine ran fine, too, but the leaks drove me nuts. It's actually easier to pull the engine to reseal the whole thing rather than try to do it in-car, and you'll end up with a really nice looking product afterwards.

Nowhere Man

if you want to go about it in the car go buy your self some of that leak detector dye and a UV light and see where its coming from

FLYNAVY30

My apologies....crossed a few numbers....

Bore on a stock LS2 = 4.00

Piston stroke length on the factory 4.8L crank = 3.268
(rod length of 6.275)

Cylinders = 8

Resultant cubic inches = 328.535

Frankie the Fink

All the leaks I've chased down usually turn out to be valve covers gaskets, rear main seal, or, oil pressure sending unit...rarely a timing chain cover. All MUCH cheaper to fix than the price of a new engine...

USMC 0802

I agree. While I think the BB of the day were badass, I'm a fan of less weight over the front wheels for overall balance. Today's small blocks make a ton of reliable power; my recent 385 HP crate motor swap in my '66 saved at least 65lbs between the heads, water pump and intake over the old iron lump.

OP- pick your poison!
(And post pics)

63 340HP

This is a good plan if leaks are the issue.

You already have a good block and heads. You have options.

A 383 will make more torque and power, but at about 600 rpm less. They do not like 7000 rpm, but can make 430hp at 6000 rpm with good off idle torque using the right combination of parts.

If you like 7000 rpm, a revised 350 can make 400hp at 6000 rpm, or 430hp at 6600 rpm. The valve train takes a beating if you keep it pegged long, but it is all doable and proven.

The cost to rebuild the 350/383 with this level of power can range from $2,500 to $5,000, much less than a LS swap.

Like many have said, 400hp in a 3100 pound car can keep up with most modern 450hp Mustangs, Challengers, and Camaros, that all weigh around 4000 pounds (lots of safety weight in a modern car). The modern cars have wider rubber, so play from a roll and save the tire smoke and driveline. You have enjoyed the car, make it tight and enjoy it more.

Randy G.

This is the 383 I used. Came with a dyno sheets and warranty. 435 hp, 465 ft lbs of torque was on my sheet, so the add numbers are conservative. Runs very strong and doesn't leak a drop. I used the "Right Stuff" on the manifold ends and corners. They are priced at $3999 now. I got mine from Summit which included shipping about 18 months ago for around $3,890.





Here's the link.

http://blueprintengines.com/index.ph...ecs-bp38313ct1




.

R66

Being an old fart, I have to apologize for being behind the times, and forgetting the fun we had.

I have a 350 with a 350 hp or so cam in our 68RS with over 120,000 miles on it. Raced the engine in a 71 Vega for a few years before stuffing it in the Camaro with the new weak kneed cam to make it streetable.

Ran 28 x 11.5" slicks on the Vega and it was a real fun 12 second car. But, driving it on the street was a nightmare. New technology with electronic fuel injection and computer controlled ignition is almost maintenance free.

But, remember, you are still dealing with 50 year old drivetrain design.

Oil leaks are a pain. A dye and black light after cleaning everything off will show you where it is coming from. You may not even have to pull the engine. The front crank seal (harmonic balancer wear) at the timing cover, valve covers, rear main, and pan are the most common problems. The plug behind the cam is a problem if it was not properly installed.

If you want the extra HP, go for it and if you don't put wrinkle wall slicks on it, you will probably be ok with minor breakage. Keep in mind if you can't get the HP to the ground, it won't help you go faster but will spin the tires and slow you down.

If it is primarily the oil leaks, dye it and tell the guys where it is coming from (I think you will know) they will help.

Ron