Hi all,

I'm working on a 1968 Camaro running a full DSE subframe and suspension. The application is a street car with the annual drag/track fun. I'll probably drive it twice a week to work and on the weekends just for fun.

I also currently have a T-56 Magnum.

My dilemma is that I'm trying to decide between a crate/stock LS7 and LS9.

I want to keep it completely stock so that I can take advantage of the GM 2Y/50K warranty.

I'm completely aware of the raw number differences between the engines.

427 vs 376
505HP vs 628HP
470TQ vs 604TQ
NA vs SC
Both dry sump
$13K vs $20K

What other decision points am I missing here? I really wish that I could drive each engine and "feel" it. That is what I am really missing, but I believe it would be nearly impossible to experience that before I make a decision.

Is there something else I should be considering?

I'm aware of the highly talked about valve spring problems with the LS7. However it seems that the LS9 doesn't have such gossip or problems. But I also understand the fact that not many people can afford the LS9 or a ZR1, so the sample size when compared to the LS7 or even an LS3 is much smaller, thus problems less likely to be reported.

There also seems to be some trickiness in the bolt pattern of the crankshaft. 6-bolt vs 8-bolt. This would impact what type of clutch kit is used with the T-56. I've heard that McLeod makes a clutch kit for the LS9 and T-56, but doesn't work very well because it's taller than the stock GM clutch kit.

Can someone that has actually driven and experienced the LS7 and LS9 please share with me some of their thoughts and experiences?

I'm looking at the torque numbers of the LS7 and have a gut feeling it won't be enough to really make the car pull hard like a freight train. The torque on the LS9 look much more appealing.

Is it worth moving up to the LS9?

Is there any drawbacks moving to the LS9 (besides cost)?

Thank you in advance

 

Bump for you -- would love to hear some of the responses.

 

Anyone have some thoughts or experience here?

 

I just wish I had the opportunity to make such a decision!

 

Checkout the Mast crate engine line with controllers. They come with an 18 month unlimited mileage warranty and are handbuilt, dyno tested engines.

LS3 416 HO 550hp/550tq - $14,495 with engine management system.
http://www.mastmotorsports.com/view.php?id=71&c=3&s=6

LS7 427 SS 650hp - $18,995 with engine management system
http://www.mastmotorsports.com/view.php?id=79&c=4&s=6

 

If you have the $.... LS9 without blinking an eye.

Once that warranty expires you run a smaller pulley, get the blower snout ported, do a larger cam, and then it'll really pull like a freight train. To gain more power out of the LS7 will cost much more than that.

 

"If you have the $.... LS9 without blinking an eye." as GNX7 said.
I've drive both and modified both, you can't go wrong with either choice. BUT without a doubt the LS9 is the Cats ***!
The LS7 is very nice, strong 7000rpm motor, BUT the LS9 pulls like a freight train from down low say, 2600 rpm then the torque jumps up to 500ft-lb by 2900rpms to about 545ft-lb and stays there till near 5500rpm IIRC. I guaranty you will have a simile on your face from ear to ear every time you drive the LS9, its a mood changer. You will definitely need R compound tires!
DO IT!

 

I'd prefer a sdpc ls7(modded) to 600-650rwhp... Otherwise if I was feeling crazy an LS7 built to handle an LS9 blower.

For me, an LS7 modded would be the bare minimum. I like that I could do this N/A and not add any weight over my ls1. That is what I would prefer.

 

I literally just crapped my pants when I read those prices...wow

 

my neighbor owns a c6-z06 and a c6-zr1. He said there is a very noticable difference in power. If you want to talk to him I'll give you his email or screen name on the corvette forum

 

Stock for stock get the LS9...if you don't mind modifying go with the LS7

 

Hmm . . . I say get the LS7 427, then spend the $7000 difference between it and the LS9 to supercharge the LS7, after the 2 year warranty runs out !!!