495HP or 505HP?

EDIT: 525HP, not 505HP

I've done a good bit of research, but I'm having a heck of a time deciding which package to go with. There's $150 price difference between the 2 with the main difference being the cams. I've been leaning towards the 495HP due to the milder cam and being easier to drive at low RPMs in general.....but $150 for an extra 30HP is a pretty nice bump too.

I'm ready to order, just can't decide. Any and all thoughts on this are welcome, good or bad.

495HP
Chevrolet Performance Parts - 19301358 - GMPP LS3 376CID 495 HP Crate Engine

525HP
GMP-19256529 - Pace Performance LS3 376CID 525 HP Crate Engine

For what it's worth it'll be hooked up to a Graz transaxle from RCR. The exhaust will come from them as well and pretty sure it'll be side exit as I prefer the cleaner look, although I'm sure louder. Just have to figure out, some how, if I'm forced to run cats when I first register the car...
 
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Julian

Lifetime Supporter
I have learnt the hard way to opt for drive ability over shear power, that is unless you are building a track dedicated car.

Per the thread title 495 to 505HP is a 10HP difference?
 
Dang it typo.... 525HP, not 505. Sorry!

475ft/lb vs 489ft/lb respectively.

I also meant to add the links to said engines as well, revised original post with them.
 

PeteB

GT40s Supporter
I'm confused - when did the LS376/480 get upgraded to 495HP? The 480 in LS376/480 stands for 480HP. Mine's only rated at 480HP - I want my extra 15HP!!!

Anyways, unless they changed the tune (maybe that's where the extra 15HP comes from?), you're going to need a $300+ dyno tune with the 376/480 in order to get it to idle, so the 525 is cheaper in the long run.
 

HCF - John

Gearbox / Brake Systems
I opted for the 525 in mine.

Check out Chevy Performance page linked for dyno comparisons of the two. They're not on the same scale, but you can see the 480/495 motor has earlier torque ramp at 3k, which then falls off quite a bit in the upper rpms. The 525 torque curve ramped up slightly later, but higher, flatter and didn't drop off.

Since the LS3 already has plenty of low end torque, I didn't see a later peak being a negative. When mine was retuned recently, it picked up another 25hp.

I'm one vote for the 525 motor! Not much of a lope and fine streetability.

Infinite - are you planning to run a drop gear set in your Graziano?
Best,
John
 
I'm confused - when did the LS376/480 get upgraded to 495HP? The 480 in LS376/480 stands for 480HP. Mine's only rated at 480HP - I want my extra 15HP!!!

Anyways, unless they changed the tune (maybe that's where the extra 15HP comes from?), you're going to need a $300+ dyno tune with the 376/480 in order to get it to idle, so the 525 is cheaper in the long run.

Me too on how and why it gained a 15hp bump. Honestly with either engine it'll get a dyno tune just because I'm sure they have to leave some HP on the table. I'm just guessing but I'd assume there may be a few things I'd need turned off as well?

I opted for the 525 in mine.

Check out Chevy Performance page linked for dyno comparisons of the two. They're not on the same scale, but you can see the 480/495 motor has earlier torque ramp at 3k, which then falls off quite a bit in the upper rpms. The 525 torque curve ramped up slightly later, but higher, flatter and didn't drop off.

Since the LS3 already has plenty of low end torque, I didn't see a later peak being a negative. When mine was retuned recently, it picked up another 25hp.

I'm one vote for the 525 motor! Not much of a lope and fine streetability.

Infinite - are you planning to run a drop gear set in your Graziano?
Best,
John

Maybe I'm just over thinking things trying to decide between the 2 engines, but just stuff I've read about the ASA cam got me worried. As far as drop gears I'm not entirely sure yet. I'll likely try stuff out as is at first and then decide, but it seems that people with them like them.

On a side note, some how the stars lined up and my brother is at the point to buy the same engine for his 79 C3 as well. I asked Pace if they'd be willing to do a discount if ordering 2 engines and they would knock $500 off the total. And I believe I've actually found a 3rd person wanting the same engine for his 69 Camaro. Still waiting to hear back on discount for 3 engines bought at same time. Both if them are going 525, so kinda pushes me to get one too although theirs will have an automatic behind it.
 

HCF - John

Gearbox / Brake Systems
Me too on how and why it gained a 15hp bump. Honestly with either engine it'll get a dyno tune just because I'm sure they have to leave some HP on the table. I'm just guessing but I'd assume there may be a few things I'd need turned off as well?



Maybe I'm just over thinking things trying to decide between the 2 engines, but just stuff I've read about the ASA cam got me worried. As far as drop gears I'm not entirely sure yet. I'll likely try stuff out as is at first and then decide, but it seems that people with them like them.

On a side note, some how the stars lined up and my brother is at the point to buy the same engine for his 79 C3 as well. I asked Pace if they'd be willing to do a discount if ordering 2 engines and they would knock $500 off the total. And I believe I've actually found a 3rd person wanting the same engine for his 69 Camaro. Still waiting to hear back on discount for 3 engines bought at same time. Both if them are going 525, so kinda pushes me to get one too although theirs will have an automatic behind it.

If you want an opinion from someone who's driven both, ping Allan U.

Regardless of what you pick, I'm sure you'll be happy with whatever you choose.
 
That's a good idea, he'd be perfect for an opinion.

I still can't figure out why Pace's 525 is $1100 cheaper than jegs or summits engines. Only difference I see is 1yr vs 2yr warranty.

A buddy of mine has a C5 FRC twin turbo 427 m6 trans that's putting out a little over 1000rwhp. His cam is pretty close in specs to the ASA and offered to let me drive his car so I can have personal experience with some what how it'd feel to putt around so I can gauge what I think. At least I know if I hate his, I definitely would like that cam in a smaller cubed engine. Plus it's not everyday​ I'd get to drive 1000rwhp car, but I'd be more excited for him to take me for a ride so I can experience what that much HP feels like.
 
Is everyone sure about these GM performance crate engine warranty periods. I don't want to share missinformation but ive read elsewhere that unless gm's installing and/or it's going into a GM vehicle that already had that engine type, it changes the warranty period...Possibly to 30 days. That's not even considering how even a basic tune would affect it. (If really 30 days...who cares). See Attached warranty. With the number of crate engines going in around here, I'm sure someone knows for sure.

That being said I'd do the 525 (but consider RPM range this will live at).
 

Attachments

  • GM_Warranty.pdf
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I'm personally not doing it for the warranty as it'll possibly be expire by the time I'm able to be alot of real miles on it. It's also why I'm considering the Pace cheaper version since only difference I can tell is warranty.

The RPM area is my main concern because I think I'll be within the lower RPMs 90% of the time. But even so, I don't thini you can go wrong with either choice.

Someone sent me this video and being as the cars weights are similar, makes me consider the 525 a little more than 495....but hell, it's still hard to pick.

Flyin' Miata 520 HP LS3 Swapped 'ND' 2016 Mazda MX5 - YouTube
 
Pace takes the 480 hp engine and does their own cam swap.

All the 480/495 engines use the same LS Hot Cam with identical part numbers. Same for the 525. I kinda wonder if possibly pace is over rated or summit/jegs is under rated?
 

Howard Jones

Supporter
The one dyno chart has torque above 400 ft/lb from 3000rpms all the way to 6300. Believe me when I tell you that's plenty for a 2600 pound car. Really.....REALLY... plenty. That means you can run most tracks in 4th all the way around and still be very quick.

Other wise 50 buck or so for the extra 30hp seams pretty cheap. I'd go for the 525 if the warranty/etc. stuff isn't a factor.
 
Found out a little info this morning.

After talking with Pace about the difference between the 525's they offer, while both are identical to each other in terms of specs, the more expensive one is straight from GM with 2yr warranty. The cheaper of the 2, Pace takes the stock 430hp engine and installs the ASA cam and timing cover with 1yr warranty.

In all honesty, for all I know I may be able to put some real miles on either engine before either warranty is up, so I'll likely go with the cheaper of the 2. Still kicking the rocks around about which HP level I want. I know in the back of my mind I'm over thinking stuff and should just go with the 525 and be done. I'm ordering something this week either way!
 
Here's my five pennyworth gleaned from a working life with race and high performance engines!
- don't believe manufacturer's dyno figures. There are differences in between different dyno figures even with correction factors. And, there are marketing figures!!
- always go with an engine builder/manufacturer with a good reputation for reliability and race winning products
- absolute horsepower is relatively easy but combining it with good driveability is much harder. So look at the torque curve first!
- look at your application. How often will you actually be on full throttle?
So, my advice is to be very sceptical of published figures unless you know the source has a good reputation - solid views NOT marketing hype!! And consider your objectives for the car.
Cheers
Roger Allen
 
The LS376/525 was run on the dyno by Eric and it was spot on the published values for torque and hp. These LS3 crate motors are solid performers; Allan has installed and tuned multiple 525 motors and they are all within production variation.

Going with an engine builder is a solid path but so are these GM crate motors. The LS3 motors offer a relatively painless power train solution with easy to source/install harnessing and electronics.

I do agree - be clear about your goals for the car and think about the engine/trans as a system and not individually.

Del - I would encourage you to reach out to Allan and ping him for his thoughts on which motor is the better for an SLC/Graz. If the cam in the 525 scares you then get the LS376/480 and know that your car will be less lopey and you'll have plenty of hp for any reasonable street driving.
 
Re: 495HP or 525HP?

SL-C number 17 compilation - YouTube

Here's a video that shows how the LS376/525 runs and idles out of the crate.
Search Results for 19301360 - Free Shipping on Orders Over $99 at Summit Racing
The part where it's on the dyno is during the initial tune.

I find that the idle and engine performance is much smoother than the 480.
The 480 has trouble idling unless it is tuned and has the Dakota Digital system on it. It also has power surges through the power curve (which can be tuned out).

The 525 is very fast combined with the Graziano. Ideally, properly engineered drop gears would make the combination perfect for the SL-C. 500 miles of driving on the 525 and it has preformed perfectly making it in my opinion the ideal engine for the SL-C.
 
Re: 495HP or 525HP?

SL-C number 17 compilation - YouTube

Here's a video that shows how the LS376/525 runs and idles out of the crate.
Search Results for 19301360 - Free Shipping on Orders Over $99 at Summit Racing
The part where it's on the dyno is during the initial tune.

I find that the idle and engine performance is much smoother than the 480.
The 480 has trouble idling unless it is tuned and has the Dakota Digital system on it. It also has power surges through the power curve (which can be tuned out).

The 525 is very fast combined with the Graziano. Ideally, properly engineered drop gears would make the combination perfect for the SL-C. 500 miles of driving on the 525 and it has preformed perfectly making it in my opinion the ideal engine for the SL-C.

SOLD! Thanks for beating me to PM'ing you. :thumbsup: That's exactly what I needed to know and now feel all warm and fuzzy inside about the 525. :) I don't think I'll have any major regrets with either one, but didn't want to pass up cheap horsepower or make it difficult to drive.

Thanks to everyone for helping with this thread. This has got to be one of the best forums around with people helping. It's getting close to being able to start my build, hope to have it within a month and when it does arrive I've already scheduled a week of vacation to get a jump on it.
 
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