Question: 72 LS-5 Engine Replacement Project

[paz72vette]

72 LS-5 Engine Rebuild/Replacement Project

All, I am thinking of rebuilding my LS-5. My cousins are talking me out of it and telling me to replace it with modern technology. New vs Old? pro vs cons? The newer vettes run like a vette should.

thankz

paz

 

[Vettehead Mikey]

Your question is pretty vague. Got some specifics?

 

[pooldaze]

what ur asking is a little vague.
First what do u want. Its ur car. I have a 72 BB and its stock number matching. and i get why dont u do this or that all the time. Its mine. Its the way i want it.
Is the car stock and original as it sits? You want to keep it that way or modifiy it? Are u looking for just an performance HP gain. Or u looking for a better handling car.
What motor would u put in.
Regarding rebuilding the 454. You can easily build 400 RWHP and keep ur tranny, pulleys, etc. Simply rebuild or replace parts on existing block.
Options for 454 is rebuild, bigger cam or roller cam, alum heads, manifold, carb, headers, exhaust. And u retain ur accessories.
If u go with a newer motor or crate motor u need to replace ur accessories, mounts, tranny, etc. The list is longer then a rebuild and more money.
Feel free to shoot me an email.

 

[Rodney Gold]

1972 ls5 was a low hp version of the 454 - rebuild it and you can easily get another 150hp out of and have a tyre smoking monster.

 

[TimAT]

For near the same cash, you can get a stroker kit- new forged crank, new forged pistons & rods, all the bearings and gaskets, as you lay out for the stock parts. It's no step to take a 454 to 496- and the jump in power is pretty amazing. Even without spending a big pile on heads.

 

[paz72vette]

Tim,

what rims do you have on you 69?

 

[Crimson Thunder]

I agree with Tim. If you rebuild the LS-5, buy the stroker kit and make it a 496. If by newer technology you mean an LSx conversion i would stick with the big block. There is nothing like big-block torque in a street driven Corvette.

 

[paz72vette]

I was checking the new this morning there are a million companies that sell these things ranging from $900 to 1,500.

does anyone have any recommendations?

thankz

paz

 

[72VETTE454]

Stroker or no stroker, I'd rebuild your 454 .

 

[shark454]

I was checking the new this morning there are a million companies that sell these things ranging from $900 to 1,500.

does anyone have any recommendations?

thankz

paz

Pull the original numbers matching motor and store it. Any rebuild will want to resurface the deck and ...bang... you now have lost the matching numbers numbers.

Get another engine ane build that motor. Now you can switch back if you change your mind.

 

[TimAT]

Shark454 has a good point. If you pull the original engine and store it properly, you won't lose any value if you sell down the road.

454 blocks are not hard to come by, and there are a bunch of places that have everything from a short block to a complete dyno'd engine.

I've been looking at (and collecting parts for) a 496 myself. I've found several places that have the kits - 1600-1800 seems about average, but I'm also looking at options like a Callies crank and Oliver rods. My goal is to build a really bombproof bottom end too. Probably going into overkill for what I'll do with the car.

 

[shrekviper]

Paz (anyone)
Was the LS5 a 2-Bolt or 4-Bolt (guessing 2)? I'll be in the same boat when it comes to rebuild time. I have a '69 vert that came w/ a '72 LS5 block (original 427 long gone). I'd love to get out of the 270HP slump and back to the 400-500HP range w/o upgrading driveline parts. Whatever you decide, post the results so we can follow along.
Thanks
Scott

 

[damoroso]

Stick with the BB. If you change to "Modern Technology", you'll have a whole host of issues to deal with. From mounting the accessories to getting your tach to work. The BB can provide you (and your cousins) all the performance you'll ever need, with less cost, less time and much less hassle. That big block is very capable and you have the chance to build it the way you want. To me, the beauty of a big block (besides the sound and torque) is that for relatively low dollars you can get tons of performance in a reliable, streetable engine. Plus they look cool as hell!

I would suggest upgrading the trans though. Go to a 5 speed if you've currently got a 4 speed or go to a 4 speed auto od if you're currently an automatic. That way you'll improve your highway performance and fuel economy, but still have tons of HP and torque to use in the lower gears.

 

[Hib Halverson]

On the "rebuild the old" vs "replacing it with the new" question...

First thing you need to decide is if, with this 72 of yours, it's important to keep the car stock or near stock. If that's the case, forget fitting it with a modern powertrain.

Next, you need to set a budget. Converting it to, say and LS3 cratemotor and a 4L60E or T56 transmission is going to cost far more than rebuidling the existing LS5. Wild-assed guess is a performance-street rebuild for the LS5 might run you 3000 bucks. To swap in an LS3 and a modern six-speed manual might coast you twice that or more.

Decide those issues first, then come back for more questions.

In the meantime, for your reading enjoyment, find a copy of CarTech's "How to Swap GM LS Series Engines into Anything". It's got a lot of information about updating older cars with modern powertrains.

 

[navy2kcoupe]

Might want to think about one of these. All new parts, and way more HP.

Found them at....
http://www.crateenginedepot.com/store/category.aspx?SID=1&Category_ID=2&Page=3
but I'm sure that there are other places......maybe one close to you.
Keep the original in case you decide to sell it, or put it back to stock.
Andy

 

[orlandjoe]

I went with a "jasperengines.com" long block 454 cu in for my 66 coupe since the origional engine was long gone. They delivered right to my door and placed the pallet right under my hoist in the garage. I was really satisfied with the long block and the service. Added dual quads, headers, Mallory ignition and a Tremic 5-speed and have a great driver. Oh, and needed a large BeCool radiator to keep things cool. Merry Christmas.

 

[baxsom]

I went with a "jasperengines.com" long block 454 cu in for my 66 coupe since the origional engine was long gone. They delivered right to my door and placed the pallet right under my hoist in the garage. I was really satisfied with the long block and the service. Added dual quads, headers, Mallory ignition and a Tremic 5-speed and have a great driver. Oh, and needed a large BeCool radiator to keep things cool. Merry Christmas.

i did the same thing, their class 2 454 rates at 430hp and 500 lb/ft of torque. the shop that did the swap also boiled the radiator, replaced the control arm bushings, and did a full alignment for 6500 total. with the 3 year warranty that comes with the engine, thats not a bad price

 

[orlandjoe]

Here's a shot of the 454 which just fits under the 66 big block hood...

 

[6880 Mike]

...I am thinking of rebuilding my LS-5. My cousins are talking me out of it...

Stop listening to your cousins.