Clay master

New to the forum currently have a c5 z. . I'm looking into also getting a c3. Chrome bumper. Saw a ls5 big block on e bay. Thoughts ,, concerns. Thanks

grahambb

link?

nonracer

LS5 is only 390 hp in stock form not very much for a BB, I guess it comes down to your plans for the car and budget.

BBCorv70

I spotted a few out there, most struck me as quite over priced. We'd need to know specifically which one you're referring to..

Faster Rat

My thoughts and/or concerns about an LS5?

I think you need to drive or go for a ride in one if you have not already done so. You may be impressed, or you may be disappointed, or you may be a little of both...after driving your comfortable and smooth C5z. Thankfully I have never driven a vette newer than '75 so I have nothing to compare it to. Ignorance is sometimes bliss.

I think that those who speak of 390 hp being too little power (for a big block) are not speaking from experience. Some of the horsepower junkies on here have even referred to them as "lump" and "junkyard truck motors." There is a reason why so many more of them were produced from '66 to '74 than the other big block variants...they were streetable, affordable, maintainable, insurable and capable of staying in one piece until at least February of 2012.

Personally, I like 427 big blocks...any and all of them. My rebuilt original L36 needs bigger rear tires than P235-60 Goodyears. I would venture to say that many original motors are long gone and many of those that still exist have been rebuilt. Those that have not are probably in need of something being done. Even the last LS5 produced is 38 years old.

I have no concerns about any vette other than my own. I can't afford to.

BBCorv70

I want to add the big blocks generate gobs of torque at low RPM. IMO great for the street. They will drive very differently from a small block. Best to test drive one yourself, make up your own mind if this is what you want. It's going to be YOUR car...

HamadUP

a 454 will produce more power than the 427 given everything else is the same, a 454 is just a stroked version of the 427, why GM stroked the 427 to 454 and yet rated it with the same HP? I don't know!.

Easy Mike

Be extremely wary of buying a car you cannot see or inspect.

427basketcase

Simple - Insurance, or the ability to insure.

Remember they had to get government / insurance co. blessing on the "Under rated HP"

Faster Rat

Chevy saw the handwriting on the wall regarding emissions, insurance (there was a 10 lbs of car weight per advertised hp threshold) and the competition for sales. Buick, Olds and Pontiac were coming out with 455s and Chrysler had the 440...so you better not be caught with your pants down. If you would no longer be able to make (aka advertise) more horsepower in the future, then you better start adding cubic inches. Maybe this was the beginning of the "size matters" syndrome that has become so prevalent in our society. It has morphed into "There is no replacement for displacement" in the automotive world...but we all know the advent of turbo and super charging has changed the rules of the game forever.

I pretty much left the scene in the summer of '69 and didn't get back until the summer of '72. Therefore I was never involved with 454s. To me, their mere introduction itself signalled the end of the muscle car as I and most of the car guys I hung with knew it...the car makers last resort before throwing in the towel. The few LS6s produced in '71 were an exception to the edict from upper level management...kill the beast. The Arab Oil Embargo in '73 just sealed the deal.

By the way, horsepower ratings were just that...a marketing tool. As to the actual measured output of each and every block that came down the line...as tested without carburetion and running on natural gas...don't get your hopes up. They were only run for a few seconds to verify function...certainly no dyno test. Few probably met the stated objective, but I have no firsthand information to confirm this.

nonracer

I misread your post I thought you were looking to buy an LS5 engine not a complete car, thats why I mentioned the hp rating figuring you could get a better engine for your budget. BTW Ive driven street cars with everything fron 56hp to well over 700 hp and a 390hp car could be extremely fun to drive.

Clay master

Thank you all for your helpful information.

Clay master

Thank you for all your helpful replies. I'm just not sure if I should hold out and find a big block. Or just stay basic with a small block. I'm looking for a c3 with sidepipes. Blue. Convertible Frame off restored. Still up in the air with the motor size. Can anyone recommend a car with these options??

BBCorv70

Have you driven both a big block and a small block Corvette? They are different animals. I think you should try both of them out, decide which one you prefer, then look for one which fits your budget.

I've owned both, prefer the big block for it's torque at low RPMs and the rumble. That's me, what I prefer. Others would rather drive a small block.

Next question is whether matching numbers is important to you. If they are, be aware a true matching numbers big block will command a premium price. There's a lot of motivation to fake these cars. For that kind of money, best have a pro inspect the stamp pad to boost confidence you're getting what you're paying for. This may be a factor as well.

If numbers are not a concern, there are big block Vettes out there which do not have the original engine (NOM). Some were originally built with big blocks, IMO, when considering NOMs, preferred. You could pick one up cheaper.

Condition is important for either, gems or junk in either category.

RS16017

I have a '71 Corvette that was a LS5(365hp) 4 speed car. The original engine was long gone before I got it. The casting number on the existing block says it's a '95 truck block. Motor's been rebuilt, sounds stock and runs good. My question is, what would be the difference internally from a '71 LS5 and my '95 truck engine?

derekderek

Please look up old threads for info, then start a new thread with your question. 95 truck engine. Efi. TBI most likely. No mechanical fuel pump or ability to mount one. Round Port heads. Max out about 4500 RPM's. Does the car have a carb on it? What intake? Pull valve covers and get cylinder head casting numbers. What fuel pump and where is it mounted? Post pics.

Vette5311

cv67

Defnitely, both will feel way differently than what you have now. Big blocks and sidepipes just go hand in hand. A sbc can sound good with them, a big block thunders....its a tone you gotta hear.
If you love torque meaning pressed back in the seat without having to floor it or run a lot of rpm youll love the big block. Been many yrs since Ive had one, would grab one in a hot second, nobody really cars about mpg with a toy anyways.

Most of all Id post here or in the regional section to see if a member who really knew what to look for could inspect it for you. THere are many many things to look for that can make it a happy day or complete loss once youve bought it. They are pretty old so sight unseen, for me would be out of the quesiton.